Virtual server agent load balancing

ABSTRACT

Virtual machine (VM) proliferation may be reduced through the use of Virtual Server Agents (VSAs) assigned to a group of VM hosts that may determine the availability of a VM to perform a task. Tasks may be assigned to existing VMs instead of creating a new VM to perform the task. Furthermore, a VSA coordinator may determine a grouping of VMs or VM hosts based on one or more factors associated with the VMs or the VM hosts, such as VM type or geographical location of the VM hosts. The VSA coordinator may also assign one or more VSAs to facilitate managing the group of VM hosts. In some embodiments, the VSA coordinators may facilitate load balancing of VSAs during operation, such as during a backup operation, a restore operation, or any other operation between a primary storage system and a secondary storage system.

RELATED APPLICATIONS

This disclosure claims the benefit of priority under 35 U.S.C. §119(e)of U.S. Provisional Patent Application No. 61/750,255, filed on Jan. 8,2013, and titled “VIRTUAL MACHINE MANAGEMENT IN A DATA STORAGE SYSTEM,”the disclosure of which is hereby incorporated by reference in itsentirety. Further, this disclosure is related to the followingdisclosures that were filed on Jan. 6, 2014, the same date as thepresent disclosure, and which are hereby incorporated by reference intheir entirety herein: U.S. application Ser. No. 14/148,465, titled“VIRTUAL MACHINE MANAGEMENT IN A DATA STORAGE SYSTEM” and U.S.application Ser. No. 14/148,549, titled “VIRTUAL MACHINE CATEGORIZATIONSYSTEM AND METHOD.”

BACKGROUND

Businesses worldwide recognize the commercial value of their data andseek reliable, cost-effective ways to protect the information stored ontheir computer networks while minimizing impact on productivity.Protecting information is often part of a routine process that isperformed within an organization.

A company might back up critical computing systems such as databases,file servers, web servers, and so on as part of a daily, weekly, ormonthly maintenance schedule. The company may similarly protectcomputing systems used by each of its employees, such as those used byan accounting department, marketing department, engineering department,and so forth.

Given the rapidly expanding volume of data under management, companiesalso continue to seek innovative techniques for managing data growth, inaddition to protecting data. For instance, companies often implementmigration techniques for moving data to lower cost storage over time anddata reduction techniques for reducing redundant data, pruning lowerpriority data, etc.

Enterprises also increasingly view their stored data as a valuableasset. Along these lines, customers are looking for solutions that notonly protect and manage, but also leverage their data. For instance,solutions providing data analysis capabilities, improved datapresentation and access features, and the like, are in increasingdemand.

In certain environments, data storage operations can be implemented withthe use of virtual machines. As such virtual machines are generallyallocated physical resources for operational purposes, excessiveutilization numbers of virtual machines can limit a system's availableresources. Furthermore, inefficient allocation/use of virtual machinescan affect a system's operational capacity. Therefore, effective virtualmachine management may be a concern in data storage systems.

SUMMARY

For purposes of summarizing the disclosure, certain aspects, advantagesand novel features of the inventions have been described herein. It isto be understood that not necessarily all such advantages may beachieved in accordance with any particular embodiment of the inventionsdisclosed herein. Thus, the inventions disclosed herein may be embodiedor carried out in a manner that achieves or optimizes one advantage orgroup of advantages as taught herein without necessarily achieving otheradvantages as may be taught or suggested herein.

In large enterprise environments, numerous virtual machines (VMs) may beinstantiated. Often, a number of virtual machines may remain unused ormay be left running after a user or system has completed accessing thevirtual machine. This proliferation of virtual machines can result inwasted resources. Further, managing backup of a primary storage systemto a secondary storage system can be complicated and require significantresources due at least in part to the proliferation of virtual machines.

In order to address the above and other challenges relating to virtualmachine proliferation, an information management system is provided thatincludes a number of virtual server agents (VSAs) and a VSA coordinatorthat can reduce VM proliferation. A job or task to be performed by avirtual machine may instead be provided to a VSA, which can identify anavailable VM to perform the task. If a VM is not available, a new VM maybe created within a set of VM host systems. However, if an existing VMhas resources available to process the task, the VSA may provide thetask to the existing VM. Advantageously, in certain embodiments, byproviding tasks to existing VMs, the number of VMs instantiated in theinformation management system are reduced.

In some implementations, VMs or VM host systems are grouped based on oneor more factors. For example, VM host systems may be grouped based onthe capabilities available to the VM host system and/or VMs hosted bythe VM host system. The groups of VMs or VM host systems may then beassigned or associated with one or more VSAs to help manage joballocations to VMs within the group.

In some embodiments, the VSA coordinator facilitates load balancing ofthe VSAs. During a backup process, the VSA coordinator may identify anumber of VSAs available to help backup a set of VMs from a primarystorage system to a secondary storage system. The VSA coordinator mayallocate the VMs among the available VSAs based on a number ofcommunication streams between each VSA and systems of the secondarystorage system. Further, in some cases, the VSA coordinator determinesan allocation of the VMs based on characteristics of the VMs to bebacked up, such as the type of VM or the size of the VM.

Certain embodiments described herein include a method of reducingvirtual machine proliferation. The method may include receiving a jobrequest at a virtual server agent. This virtual server agent may includecomputer hardware. Further, the method may include determining a loadfor each virtual machine from a set of virtual machines. The set ofvirtual machines may be at least partially managed by the virtual serveragent. In addition, the method may include determining whether the loadof at least one virtual machine from the set of virtual machines isbelow a threshold load. In response to determining that the load of atleast one virtual machine from the set of virtual machines is below thethreshold load, the method may include selecting a virtual machine froma set of virtual machines with a load that is below the threshold loadand assigning a job associated with the job request to the selectedvirtual machine. Further, in response to determining that no virtualmachine from the set of virtual machines is below a threshold load, themethod can include initiating creation of a new virtual machine andassigning the job associated with the job request to the new virtualmachine.

In some embodiments, a system for reducing virtual machine proliferationis disclosed. The system can include a virtual server agent comprisingcomputer hardware. The virtual server agent may be configured to receivea job request and to access load information for each virtual machinefrom a set of virtual machines assigned to the virtual server agent.Further, the virtual server agent may identify, based at least partiallyon the load information for each virtual machine, a subset of virtualmachines from the set of virtual machines with a load below a thresholdload. In addition, the virtual server agent can select a virtual machinefrom the subset of virtual machines and assign a job associated with thejob request to the selected virtual machine when the subset of virtualmachines is a non-empty set.

Certain embodiments described herein include a method of groupingvirtual machines. The method may be performed by a virtual server agentcoordinator comprising computer hardware. The method can includeidentifying a set of virtual machine provider systems in a primarystorage system. Each of the virtual machine provider systems may includea virtual machine monitor and may be configured to host a set of virtualmachines. Further, the method can include accessing metadata for each ofthe virtual machine provider systems from the set of virtual machineprovider systems. In addition, the method may include grouping thevirtual machine provider systems into one or more groups based at leastpartially on the metadata for each of the virtual machine providersystems. Moreover, the method can include assigning a set of virtualserver agents to each group of virtual machine provider systems. Eachvirtual server agent may be configured to backup data from at least onevirtual machine in the primary storage system to a secondary storagesystem.

In some embodiments, a system for grouping virtual machines isdisclosed. The system may include a virtual server agent coordinatorcomprising computer hardware. The virtual server agent coordinator maybe configured to identify a set of virtual machine provider systems in aprimary storage system. Each of the virtual machine provider systems mayinclude a virtual machine monitor and may be configured to host a set ofvirtual machines. Further, the virtual server agent coordinator mayaccess metadata for each of the virtual machine provider systems fromthe set of virtual machine provider systems. In addition, the virtualserver agent coordinator can group the virtual machine provider systemsinto one or more groups based at least partially on the metadata foreach of the virtual machine provider systems. Moreover, the virtualserver agent coordinator can assign a set of virtual server agents toeach group of virtual machine provider systems. Each virtual serveragent may be configured to backup data from at least one virtual machinein the primary storage system to a secondary storage system.

Certain embodiments described herein include a method of virtual serveragent load balancing. The method may be performed by a virtual serveragent coordinator comprising computer hardware. The method may includeidentifying a set of virtual machines for backup to a secondary storagesystem. The set of virtual machines may be hosted by a set of virtualmachine provider systems. Further, the set of virtual machine providersystems may be included in a primary storage system. The method may alsoinclude identifying a set of virtual server agents available to backupdata from the set of virtual machines to the secondary storage system.Further, the method may include determining a number of data streamsavailable to each virtual server agent from the set of virtual serveragents. Moreover, the method may include distributing the set of virtualmachines among the set of virtual server agents based at least partiallyon the number of data streams available to each of the virtual serveragents.

In some embodiments, a system for virtual server agent load balancing isdisclosed. The system may include a virtual server agent coordinatorcomprising computer hardware. Further, the virtual server agentcoordinator may be configured to identify a set of virtual machines forbackup to a secondary storage system. The set of virtual machines may behosted by a set of virtual machine provider systems. Further, the set ofvirtual machine provider systems may be included in a primary storagesystem. Moreover, the virtual server agent coordinator may identify aset of virtual server agents available to backup data from the set ofvirtual machines to the secondary storage system. In addition, thevirtual server agent coordinator may determine a number of data streamsavailable to each virtual server agent from the set of virtual serveragents. Moreover, the virtual server agent coordinator can distributethe set of virtual machines among the set of virtual server agents basedat least partially on the number of data streams available to each ofthe virtual server agents.

BRIEF DESCRIPTION OF THE DRAWINGS

Throughout the drawings, reference numbers are re-used to indicatecorrespondence between referenced elements. The drawings are provided toillustrate embodiments of the inventive subject matter described hereinand not to limit the scope thereof.

FIG. 1A is a block diagram illustrating an exemplary informationmanagement system.

FIG. 1B is a detailed view of a primary storage device, a secondarystorage device, and some examples of primary data and secondary copydata.

FIG. 1C is a block diagram of an exemplary information management systemincluding a storage manager, one or more data agents, and one or moremedia agents.

FIG. 1D is a block diagram illustrating a scalable informationmanagement system.

FIG. 1E illustrates certain secondary copy operations according to anexemplary storage policy.

FIGS. 1F-1H are block diagrams illustrating suitable data structuresthat may be employed by the information management system.

FIG. 2 is a block diagram illustrating an example of a scalableinformation management system.

FIG. 3 illustrates a flowchart for an example virtual machine joballocation process.

FIG. 4 illustrates a flowchart for an example virtual machine groupingprocess.

FIG. 5 illustrates a flowchart for an example virtual server agent loadbalancing process.

DETAILED DESCRIPTION

Systems and methods are described herein for reducing virtual machine(VM) proliferation, grouping virtual machines, and load balancingvirtual server agents (VSAs). Examples of such systems and methods arediscussed in further detail herein, e.g., with respect to FIGS. 2-5.Moreover, it will be appreciated that reducing VM proliferation,grouping VMs, and load balancing VSAs may be implemented by informationmanagement systems, such as those that will now be described withrespect to FIGS. 1A-1H. Further, as will be described, the componentsfor implementing a reduction in VM proliferation, grouping VMs, and loadbalancing VSAs can be incorporated into such systems.

System Overview

The system and methods described with respect to FIGS. 1A-1H can be usedfor implementing a reduction in virtual machine proliferation. In someembodiments, one or more VSAs assigned to a group of virtual machinehosts (e.g., client computing devices and server computing devices) maydetermine the availability of a VM to perform a task or job. Thus, tasksmay be assigned to existing VMs instead of creating a new VM to performthe task. Furthermore, systems and methods for grouping virtual machinehosts are also disclosed herein. In some embodiments, a VSA coordinatormay determine a grouping of VMs or VM hosts based on one or more factorsassociated with the VMs or the VM hosts, such as VM type or geographicallocation of the VM hosts. The VSA coordinator may also assign one ormore VSAs to facilitate managing the group of VM hosts. In someembodiments, the VSA coordinators may facilitate load balancing of VSAsduring operation, such as during a backup operation, a restoreoperation, or any other operation between a primary storage system and asecondary storage system.

Information Management System Overview

With the increasing importance of protecting and leveraging data,organizations simply cannot afford to take the risk of losing criticaldata. Moreover, runaway data growth and other modern realities makeprotecting and managing data an increasingly difficult task. There istherefore a need for efficient, powerful, and user-friendly solutionsfor protecting and managing data.

Depending on the size of the organization, there are typically many dataproduction sources which are under the purview of tens, hundreds, oreven thousands of employees or other individuals. In the past,individual employees were sometimes responsible for managing andprotecting their data. A patchwork of hardware and software pointsolutions has been applied in other cases. These solutions were oftenprovided by different vendors and had limited or no interoperability.

Certain embodiments described herein provide systems and methods capableof addressing these and other shortcomings of prior approaches byimplementing unified, organization-wide information management. FIG. 1Ashows one such information management system 100, which generallyincludes combinations of hardware and software configured to protect andmanage data and metadata generated and used by the various computingdevices in the information management system 100.

The organization which employs the information management system 100 maybe a corporation or other business entity, non-profit organization,educational institution, household, governmental agency, or the like.

Generally, the systems and associated components described herein may becompatible with and/or provide some or all of the functionality of thesystems and corresponding components described in one or more of thefollowing U.S. patents and patent application publications assigned toCommVault Systems, Inc., each of which is hereby incorporated in itsentirety by reference herein:

-   -   U.S. Pat. No. 8,285,681, entitled “Data Object Store and Server        for a Cloud Storage Environment, Including Data Deduplication        and Data Management Across Multiple Cloud Storage Sites”;    -   U.S. Pat. No. 8,307,177, entitled “Systems And Methods For        Management Of Virtualization Data”;    -   U.S. Pat. No. 7,035,880, entitled “Modular Backup and Retrieval        System Used in Conjunction With a Storage Area Network”;    -   U.S. Pat. No. 7,343,453, entitled “Hierarchical Systems and        Methods for Providing a Unified View of Storage Information”;    -   U.S. Pat. No. 7,395,282, entitled “Hierarchical Backup and        Retrieval System”;    -   U.S. Pat. No. 7,246,207, entitled “System and Method for        Dynamically Performing Storage Operations in a Computer        Network”;    -   U.S. Pat. No. 7,747,579, entitled “Metabase for Facilitating        Data Classification”;    -   U.S. Pat. No. 8,229,954, entitled “Managing Copies of Data”;    -   U.S. Pat. No. 7,617,262, entitled “System and Methods for        Monitoring Application Data in a Data Replication System”;    -   U.S. Pat. No. 7,529,782, entitled “System and Methods for        Performing a Snapshot and for Restoring Data”;    -   U.S. Pat. No. 8,230,195, entitled “System And Method For        Performing Auxiliary Storage Operations”;    -   U.S. Pat. No. 7,315,923, entitled “System And Method For        Combining Data Streams In Pipelined Storage Operations In A        Storage Network”;    -   U.S. Pat. No. 8,364,652, entitled “Content-Aligned, Block-Based        Deduplication”;    -   U.S. Pat. Pub. No. 2006/0224846, entitled “System and Method to        Support Single Instance Storage Operations”;    -   U.S. Pat. No. 8,578,120, entitled “Block-Level Single        Instancing”;    -   U.S. Pat. Pub. No. 2009/0319534, entitled “Application-Aware and        Remote Single Instance Data Management”;    -   U.S. Pat. Pub. No. 2012/0150826, entitled “Distributed        Deduplicated Storage System”;    -   U.S. Pat. Pub. No. 2012/0150818, entitled “Client-Side        Repository in a Networked Deduplicated Storage System”;    -   U.S. Pat. No. 8,170,995, entitled “Method and System for Offline        Indexing of Content and Classifying Stored Data”;    -   U.S. Pat. No. 7,107,298, entitled “System And Method For        Archiving Objects In An Information Store”;    -   U.S. Pat. No. 8,230,195, entitled “System And Method For        Performing Auxiliary Storage Operations”;    -   U.S. Pat. No. 8,229,954, entitled “Managing Copies Of Data”; and    -   U.S. Pat. No. 8,156,086, entitled “Systems And Methods For        Stored Data Verification”.

The information management system 100 can include a variety of differentcomputing devices. For instance, as will be described in greater detailherein, the information management system 100 can include one or moreclient computing devices 102 and secondary storage computing devices106.

Computing devices can include, without limitation, one or more:workstations, personal computers, desktop computers, or other types ofgenerally fixed computing systems such as mainframe computers andminicomputers.

Other computing devices can include mobile or portable computingdevices, such as one or more laptops, tablet computers, personal dataassistants, mobile phones (such as smartphones), and other mobile orportable computing devices such as embedded computers, set top boxes,vehicle-mounted devices, wearable computers, etc. Computing devices caninclude servers, such as mail servers, file servers, database servers,and web servers.

In some cases, a computing device includes virtualized and/or cloudcomputing resources. For instance, one or more virtual machines may beprovided to the organization by a third-party cloud service vendor. Or,in some embodiments, computing devices can include one or more virtualmachine(s) running on a physical host computing device (or “hostmachine”) operated by the organization. As one example, the organizationmay use one virtual machine as a database server and another virtualmachine as a mail server, both virtual machines operating on the samehost machine.

A virtual machine includes an operating system and associated virtualresources, and is hosted simultaneously with another operating system ona physical host computer (or host machine). A hypervisor (typicallysoftware, and also known in the art as a virtual machine monitor or avirtual machine manager or “VMM”) sits between the virtual machine andthe hardware of the physical host computer. One example of hypervisor asvirtualization software is ESX Server, by VMware, Inc. of Palo Alto,Calif.; other examples include Microsoft Virtual Server and MicrosoftWindows Server Hyper-V, both by Microsoft Corporation of Redmond, Wash.,and Sun xVM by Oracle America Inc. of Santa Clara, Calif. In someembodiments, the hypervisor may be firmware or hardware or a combinationof software and/or firmware and/or hardware.

The hypervisor provides to each virtual operating system virtualresources, such as a virtual processor, virtual memory, a virtualnetwork device, and a virtual disk. Each virtual machine has one or morevirtual disks. The hypervisor typically stores the data of virtual disksin files on the file system of the physical host computer, calledvirtual machine disk files (in the case of VMware virtual servers) orvirtual hard disk image files (in the case of Microsoft virtualservers). For example, VMware's ESX Server provides the Virtual MachineFile System (VMFS) for the storage of virtual machine disk files. Avirtual machine reads data from and writes data to its virtual disk muchthe same way that an actual physical machine reads data from and writesdata to an actual disk.

Examples of techniques for implementing information managementtechniques in a cloud computing environment are described in U.S. Pat.No. 8,285,681, which is incorporated by reference herein. Examples oftechniques for implementing information management techniques in avirtualized computing environment are described in U.S. Pat. No.8,307,177, also incorporated by reference herein.

The information management system 100 can also include a variety ofstorage devices, including primary storage devices 104 and secondarystorage devices 108, for example. Storage devices can generally be ofany suitable type including, without limitation, disk drives, hard-diskarrays, semiconductor memory (e.g., solid state storage devices),network attached storage (NAS) devices, tape libraries or othermagnetic, non-tape storage devices, optical media storage devices,DNA/RNA-based memory technology, combinations of the same, and the like.In some embodiments, storage devices can form part of a distributed filesystem. In some cases, storage devices are provided in a cloud (e.g., aprivate cloud or one operated by a third-party vendor). A storage devicein some cases comprises a disk array or portion thereof.

The illustrated information management system 100 includes one or moreclient computing device 102 having at least one application 110executing thereon, and one or more primary storage devices 104 storingprimary data 112. The client computing device(s) 102 and the primarystorage devices 104 may generally be referred to in some cases as aprimary storage subsystem 117. A computing device in an informationmanagement system 100 that has a data agent 142 installed on it isgenerally referred to as a client computing device 102 (or, in thecontext of a component of the information management system 100 simplyas a “client”).

Depending on the context, the term “information management system” canrefer to generally all of the illustrated hardware and softwarecomponents. Or, in other instances, the term may refer to only a subsetof the illustrated components.

For instance, in some cases, the information management system 100generally refers to a combination of specialized components used toprotect, move, manage, manipulate, analyze, and/or process data andmetadata generated by the client computing devices 102. However, theinformation management system 100 in some cases does not include theunderlying components that generate and/or store the primary data 112,such as the client computing devices 102 themselves, the applications110 and operating system residing on the client computing devices 102,and the primary storage devices 104. As an example, “informationmanagement system” may sometimes refer to one or more of the followingcomponents and corresponding data structures: storage managers, dataagents, and media agents. These components will be described in furtherdetail below.

Client Computing Devices

There are typically a variety of sources in an organization that producedata to be protected and managed. As just one illustrative example, in acorporate environment such data sources can be employee workstations andcompany servers such as a mail server, a web server, or the like. In theinformation management system 100, the data generation sources includethe one or more client computing devices 102.

The client computing devices 102 may include any of the types ofcomputing devices described above, without limitation, and in some casesthe client computing devices 102 are associated with one or more usersand/or corresponding user accounts, of employees or other individuals.

The information management system 100 generally addresses and handlesthe data management and protection needs for the data generated by theclient computing devices 102. However, the use of this term does notimply that the client computing devices 102 cannot be “servers” in otherrespects. For instance, a particular client computing device 102 may actas a server with respect to other devices, such as other clientcomputing devices 102. As just a few examples, the client computingdevices 102 can include mail servers, file servers, database servers,and web servers.

Each client computing device 102 may have one or more applications 110(e.g., software applications) executing thereon which generate andmanipulate the data that is to be protected from loss and managed.

The applications 110 generally facilitate the operations of anorganization (or multiple affiliated organizations), and can include,without limitation, mail server applications (e.g., Microsoft ExchangeServer), file server applications, mail client applications (e.g.,Microsoft Exchange Client), database applications (e.g., SQL, Oracle,SAP, Lotus Notes Database), word processing applications (e.g.,Microsoft Word), spreadsheet applications, financial applications,presentation applications, browser applications, mobile applications,entertainment applications, and so on.

The client computing devices 102 can have at least one operating system(e.g., Microsoft Windows, Mac OS X, iOS, IBM z/OS, Linux, otherUnix-based operating systems, etc.) installed thereon, which may supportor host one or more file systems and other applications 110.

As shown, the client computing devices 102 and other components in theinformation management system 100 can be connected to one another viaone or more communication pathways 114. The communication pathways 114can include one or more networks or other connection types including asany of following, without limitation: the Internet, a wide area network(WAN), a local area network (LAN), a Storage Area Network (SAN), a FibreChannel connection, a Small Computer System Interface (SCSI) connection,a virtual private network (VPN), a token ring or TCP/IP based network,an intranet network, a point-to-point link, a cellular network, awireless data transmission system, a two-way cable system, aninteractive kiosk network, a satellite network, a broadband network, abaseband network, a neural network, a mesh network, an ad hoc network,other appropriate wired, wireless, or partially wired/wireless computeror telecommunications networks, combinations of the same or the like.The communication pathways 114 in some cases may also includeapplication programming interfaces (APIs) including, e.g., cloud serviceprovider APIs, virtual machine management APIs, and hosted serviceprovider APIs.

Primary Data and Exemplary Primary Storage Devices

Primary data 112 according to some embodiments is production data orother “live” data generated by the operating system and otherapplications 110 residing on a client computing device 102. The primarydata 112 is generally stored on the primary storage device(s) 104 and isorganized via a file system supported by the client computing device102. For instance, the client computing device(s) 102 and correspondingapplications 110 may create, access, modify, write, delete, andotherwise use primary data 112. In some cases, some or all of theprimary data 112 can be stored in cloud storage resources.

Primary data 112 is generally in the native format of the sourceapplication 110. According to certain aspects, primary data 112 is aninitial or first (e.g., created before any other copies or before atleast one other copy) stored copy of data generated by the sourceapplication 110. Primary data 112 in some cases is created substantiallydirectly from data generated by the corresponding source applications110.

The primary data 112 may sometimes be referred to as a “primary copy” inthe sense that it is a discrete set of data. However, the use of thisterm does not necessarily imply that the “primary copy” is a copy in thesense that it was copied or otherwise derived from another storedversion.

The primary storage devices 104 storing the primary data 112 may berelatively fast and/or expensive (e.g., a disk drive, a hard-disk array,solid state memory, etc.). In addition, primary data 112 may be intendedfor relatively short term retention (e.g., several hours, days, orweeks).

According to some embodiments, the client computing device 102 canaccess primary data 112 from the primary storage device 104 by makingconventional file system calls via the operating system. Primary data112 representing files may include structured data (e.g., databasefiles), unstructured data (e.g., documents), and/or semi-structureddata. Some specific examples are described below with respect to FIG.1B.

It can be useful in performing certain tasks to organize the primarydata 112 into units of different granularities. In general, primary data112 can include files, directories, file system volumes, data blocks,extents, or any other hierarchies or organizations of data objects. Asused herein, a “data object” can refer to both (1) any file that iscurrently addressable by a file system or that was previouslyaddressable by the file system (e.g., an archive file) and (2) a subsetof such a file (e.g., a data block).

As will be described in further detail, it can also be useful inperforming certain functions of the information management system 100 toaccess and modify metadata within the primary data 112. Metadatagenerally includes information about data objects or characteristicsassociated with the data objects.

Metadata can include, without limitation, one or more of the following:the data owner (e.g., the client or user that generates the data), thelast modified time (e.g., the time of the most recent modification ofthe data object), a data object name (e.g., a file name), a data objectsize (e.g., a number of bytes of data), information about the content(e.g., an indication as to the existence of a particular search term),user-supplied tags, to/from information for email (e.g., an emailsender, recipient, etc.), creation date, file type (e.g., format orapplication type), last accessed time, application type (e.g., type ofapplication that generated the data object), location/network (e.g., acurrent, past or future location of the data object and network pathwaysto/from the data object), geographic location (e.g., GPS coordinates),frequency of change (e.g., a period in which the data object ismodified), business unit (e.g., a group or department that generates,manages or is otherwise associated with the data object), aginginformation (e.g., a schedule, such as a time period, in which the dataobject is migrated to secondary or long term storage), boot sectors,partition layouts, file location within a file folder directorystructure, user permissions, owners, groups, access control lists[ACLs]), system metadata (e.g., registry information), combinations ofthe same or the other similar information related to the data object.

In addition to metadata generated by or related to file systems andoperating systems, some of the applications 110 and/or other componentsof the information management system 100 maintain indices of metadatafor data objects, e.g., metadata associated with individual emailmessages. Thus, each data object may be associated with correspondingmetadata. The use of metadata to perform classification and otherfunctions is described in greater detail below.

Each of the client computing devices 102 are generally associated withand/or in communication with one or more of the primary storage devices104 storing corresponding primary data 112. A client computing device102 may be considered to be “associated with” or “in communication with”a primary storage device 104 if it is capable of one or more of: routingand/or storing data to the particular primary storage device 104,coordinating the routing and/or storing of data to the particularprimary storage device 104, retrieving data from the particular primarystorage device 104, coordinating the retrieval of data from theparticular primary storage device 104, and modifying and/or deletingdata retrieved from the particular primary storage device 104.

The primary storage devices 104 can include any of the different typesof storage devices described above, or some other kind of suitablestorage device. The primary storage devices 104 may have relatively fastI/O times and/or are relatively expensive in comparison to the secondarystorage devices 108. For example, the information management system 100may generally regularly access data and metadata stored on primarystorage devices 104, whereas data and metadata stored on the secondarystorage devices 108 is accessed relatively less frequently.

In some cases, each primary storage device 104 is dedicated to anassociated client computing device 102. For instance, a primary storagedevice 104 in one embodiment is a local disk drive of a correspondingclient computing device 102. In other cases, one or more primary storagedevices 104 can be shared by multiple client computing devices 102,e.g., via a network such as in a cloud storage implementation. As oneexample, a primary storage device 104 can be a disk array shared by agroup of client computing devices 102, such as one of the followingtypes of disk arrays: EMC Clariion, EMC Symmetrix, EMC Celerra, DellEqualLogic, IBM XIV, NetApp FAS, HP EVA, and HP 3PAR.

The information management system 100 may also include hosted services(not shown), which may be hosted in some cases by an entity other thanthe organization that employs the other components of the informationmanagement system 100. For instance, the hosted services may be providedby various online service providers to the organization. Such serviceproviders can provide services including social networking services,hosted email services, or hosted productivity applications or otherhosted applications).

Hosted services may include software-as-a-service (SaaS),platform-as-a-service (PaaS), application service providers (ASPs),cloud services, or other mechanisms for delivering functionality via anetwork. As it provides services to users, each hosted service maygenerate additional data and metadata under management of theinformation management system 100, e.g., as primary data 112. In somecases, the hosted services may be accessed using one of the applications110. As an example, a hosted mail service may be accessed via browserrunning on a client computing device 102. The hosted services may beimplemented in a variety of computing environments. In some cases, theyare implemented in an environment having a similar arrangement to theinformation management system 100, where various physical and logicalcomponents are distributed over a network.

Secondary Copies and Exemplary Secondary Storage Devices

The primary data 112 stored on the primary storage devices 104 may becompromised in some cases, such as when an employee deliberately oraccidentally deletes or overwrites primary data 112 during their normalcourse of work. Or the primary storage devices 104 can be damaged orotherwise corrupted.

For recovery and/or regulatory compliance purposes, it is thereforeuseful to generate copies of the primary data 112. Accordingly, theinformation management system 100 includes one or more secondary storagecomputing devices 106 and one or more secondary storage devices 108configured to create and store one or more secondary copies 116 of theprimary data 112 and associated metadata. The secondary storagecomputing devices 106 and the secondary storage devices 108 maysometimes be referred to as a secondary storage subsystem 118.

Creation of secondary copies 116 can help in search and analysis effortsand meet other information management goals, such as: restoring dataand/or metadata if an original version (e.g., of primary data 112) islost (e.g., by deletion, corruption, or disaster); allowingpoint-in-time recovery; complying with regulatory data retention andelectronic discovery (e-discovery) requirements; reducing utilizedstorage capacity; facilitating organization and search of data;improving user access to data files across multiple computing devicesand/or hosted services; and implementing data retention policies.

The client computing devices 102 access or receive primary data 112 andcommunicate the data, e.g., over the communication pathways 114, forstorage in the secondary storage device(s) 108.

A secondary copy 116 can comprise a separate stored copy of applicationdata that is derived from one or more earlier-created, stored copies(e.g., derived from primary data 112 or another secondary copy 116).Secondary copies 116 can include point-in-time data, and may be intendedfor relatively long-term retention (e.g., weeks, months or years),before some or all of the data is moved to other storage or isdiscarded.

In some cases, a secondary copy 116 is a copy of application datacreated and stored subsequent to at least one other stored instance(e.g., subsequent to corresponding primary data 112 or to anothersecondary copy 116), in a different storage device than at least oneprevious stored copy, and/or remotely from at least one previous storedcopy. In some other cases, secondary copies can be stored in the samestorage device as primary data 112 and/or other previously storedcopies. For example, in one embodiment a disk array capable ofperforming hardware snapshots stores primary data 112 and creates andstores hardware snapshots of the primary data 112 as secondary copies116. Secondary copies 116 may be stored in relatively slow and/or lowcost storage (e.g., magnetic tape). A secondary copy 116 may be storedin a backup or archive format, or in some other format different thanthe native source application format or other primary data format.

In some cases, secondary copies 116 are indexed so users can browse andrestore at another point in time. After creation of a secondary copy 116representative of certain primary data 112, a pointer or other locationindicia (e.g., a stub) may be placed in primary data 112, or beotherwise associated with primary data 112 to indicate the currentlocation on the secondary storage device(s) 108.

Since an instance of a data object or metadata in primary data 112 maychange over time as it is modified by an application 110 (or hostedservice or the operating system), the information management system 100may create and manage multiple secondary copies 116 of a particular dataobject or metadata, each representing the state of the data object inprimary data 112 at a particular point in time. Moreover, since aninstance of a data object in primary data 112 may eventually be deletedfrom the primary storage device 104 and the file system, the informationmanagement system 100 may continue to manage point-in-timerepresentations of that data object, even though the instance in primarydata 112 no longer exists.

For virtualized computing devices the operating system and otherapplications 110 of the client computing device(s) 102 may executewithin or under the management of virtualization software (e.g., a VMM),and the primary storage device(s) 104 may comprise a virtual diskcreated on a physical storage device. The information management system100 may create secondary copies 116 of the files or other data objectsin a virtual disk file and/or secondary copies 116 of the entire virtualdisk file itself (e.g., of an entire .vmdk file).

Secondary copies 116 may be distinguished from corresponding primarydata 112 in a variety of ways, some of which will now be described.First, as discussed, secondary copies 116 can be stored in a differentformat (e.g., backup, archive, or other non-native format) than primarydata 112. For this or other reasons, secondary copies 116 may not bedirectly useable by the applications 110 of the client computing device102, e.g., via standard system calls or otherwise without modification,processing, or other intervention by the information management system100.

Secondary copies 116 are also in some embodiments stored on a secondarystorage device 108 that is inaccessible to the applications 110 runningon the client computing devices 102 (and/or hosted services). Somesecondary copies 116 may be “offline copies,” in that they are notreadily available (e.g., not mounted to tape or disk). Offline copiescan include copies of data that the information management system 100can access without human intervention (e.g., tapes within an automatedtape library, but not yet mounted in a drive), and copies that theinformation management system 100 can access only with at least somehuman intervention (e.g., tapes located at an offsite storage site).

The Use of Intermediate Devices for Creating Secondary Copies

Creating secondary copies can be a challenging task. For instance, therecan be hundreds or thousands of client computing devices 102 continuallygenerating large volumes of primary data 112 to be protected. Also,there can be significant overhead involved in the creation of secondarycopies 116. Moreover, secondary storage devices 108 may be specialpurpose components, and interacting with them can require specializedintelligence.

In some cases, the client computing devices 102 interact directly withthe secondary storage device 108 to create the secondary copies 116.However, in view of the factors described above, this approach cannegatively impact the ability of the client computing devices 102 toserve the applications 110 and produce primary data 112. Further, theclient computing devices 102 may not be optimized for interaction withthe secondary storage devices 108.

Thus, in some embodiments, the information management system 100includes one or more software and/or hardware components which generallyact as intermediaries between the client computing devices 102 and thesecondary storage devices 108. In addition to off-loading certainresponsibilities from the client computing devices 102, theseintermediate components can provide other benefits. For instance, asdiscussed further below with respect to FIG. 1D, distributing some ofthe work involved in creating secondary copies 116 can enhancescalability.

The intermediate components can include one or more secondary storagecomputing devices 106 as shown in FIG. 1A and/or one or more mediaagents, which can be software modules residing on correspondingsecondary storage computing devices 106 (or other appropriate devices).Media agents are discussed below (e.g., with respect to FIGS. 1C-1E).

The secondary storage computing device(s) 106 can comprise any of thecomputing devices described above, without limitation. In some cases,the secondary storage computing device(s) 106 include specializedhardware and/or software componentry for interacting with the secondarystorage devices 108.

To create a secondary copy 116 involving the copying of data from theprimary storage subsystem 117 to the secondary storage subsystem 118,the client computing device 102 in some embodiments communicates theprimary data 112 to be copied (or a processed version thereof) to thedesignated secondary storage computing device 106, via the communicationpathway 114. The secondary storage computing device 106 in turn conveysthe received data (or a processed version thereof) to the secondarystorage device 108. In some such configurations, the communicationpathway 114 between the client computing device 102 and the secondarystorage computing device 106 comprises a portion of a LAN, WAN or SAN.In other cases, at least some client computing devices 102 communicatedirectly with the secondary storage devices 108 (e.g., via Fibre Channelor SCSI connections). In some other cases, one or more secondary copies116 are created from existing secondary copies, such as in the case ofan auxiliary copy operation, described in greater detail below.

Exemplary Primary Data and an Exemplary Secondary Copy

FIG. 1B is a detailed view showing some specific examples of primarydata stored on the primary storage device(s) 104 and secondary copy datastored on the secondary storage device(s) 108, with other components inthe system removed for the purposes of illustration. Stored on theprimary storage device(s) 104 are primary data objects including wordprocessing documents 119A-B, spreadsheets 120, presentation documents122, video files 124, image files 126, email mailboxes 128 (andcorresponding email messages 129A-C), html/xml or other types of markuplanguage files 130, databases 132 and corresponding tables or other datastructures 133A-133C).

Some or all primary data objects are associated with correspondingmetadata (e.g., “Meta1-11”), which may include file system metadataand/or application specific metadata. Stored on the secondary storagedevice(s) 108 are secondary copy data objects 134A-C which may includecopies of or otherwise represent corresponding primary data objects andmetadata.

As shown, the secondary copy data objects 134A-C can individuallyrepresent more than one primary data object. For example, secondary copydata object 134A represents three separate primary data objects 133C,122 and 129C (represented as 133C′, 122′ and 129C′, respectively, andaccompanied by the corresponding metadata Meta11, Meta3, and Meta8,respectively). Moreover, as indicated by the prime mark (′), a secondarycopy object may store a representation of a primary data object ormetadata differently than the original format, e.g., in a compressed,encrypted, deduplicated, or other modified format. Likewise, secondarydata object 134B represents primary data objects 120, 133B, and 119A as120′, 133B′, and 119A′, respectively and accompanied by correspondingmetadata Meta2, Meta10, and Meta1, respectively. Also, secondary dataobject 134C represents primary data objects 133A, 119B, and 129A as133A′, 119B′, and 129A′, respectively, accompanied by correspondingmetadata Meta9, Meta5, and Meta6, respectively.

Exemplary Information Management System Architecture

The information management system 100 can incorporate a variety ofdifferent hardware and software components, which can in turn beorganized with respect to one another in many different configurations,depending on the embodiment. There are critical design choices involvedin specifying the functional responsibilities of the components and therole of each component in the information management system 100. Forinstance, as will be discussed, such design choices can impactperformance as well as the adaptability of the information managementsystem 100 to data growth or other changing circumstances.

FIG. 1C shows an information management system 100 designed according tothese considerations and which includes: storage manager 140, acentralized storage and/or information manager that is configured toperform certain control functions, one or more data agents 142 executingon the client computing device(s) 102 configured to process primary data112, and one or more media agents 144 executing on the one or moresecondary storage computing devices 106 for performing tasks involvingthe secondary storage devices 108. While distributing functionalityamongst multiple computing devices can have certain advantages, in othercontexts it can be beneficial to consolidate functionality on the samecomputing device. As such, in various other embodiments, one or more ofthe components shown in FIG. 1C as being implemented on separatecomputing devices are implemented on the same computing device. In oneconfiguration, a storage manager 140, one or more data agents 142, andone or more media agents 144 are all implemented on the same computingdevice. In another embodiment, one or more data agents 142 and one ormore media agents 144 are implemented on the same computing device,while the storage manager 140 is implemented on a separate computingdevice.

Storage Manager

As noted, the number of components in the information management system100 and the amount of data under management can be quite large. Managingthe components and data is therefore a significant task, and a task thatcan grow in an often unpredictable fashion as the quantity of componentsand data scale to meet the needs of the organization.

For these and other reasons, according to certain embodiments,responsibility for controlling the information management system 100, orat least a significant portion of that responsibility, is allocated tothe storage manager 140.

By distributing control functionality in this manner, the storagemanager 140 can be adapted independently according to changingcircumstances. Moreover, a computing device for hosting the storagemanager 140 can be selected to best suit the functions of the storagemanager 140. These and other advantages are described in further detailbelow with respect to FIG. 1D.

The storage manager 140 may be a software module or other application.In some embodiments, storage manager 140 is a computing devicecomprising circuitry for executing computer instructions and performsthe functions described herein. The storage manager generally initiates,performs, coordinates and/or controls storage and other informationmanagement operations performed by the information management system100, e.g., to protect and control the primary data 112 and secondarycopies 116 of data and metadata.

As shown by the dashed arrowed lines 114, the storage manager 140 maycommunicate with and/or control some or all elements of the informationmanagement system 100, such as the data agents 142 and media agents 144.Thus, in certain embodiments, control information originates from thestorage manager 140, whereas payload data and payload metadata isgenerally communicated between the data agents 142 and the media agents144 (or otherwise between the client computing device(s) 102 and thesecondary storage computing device(s) 106), e.g., at the direction ofthe storage manager 140. Control information can generally includeparameters and instructions for carrying out information managementoperations, such as, without limitation, instructions to perform a taskassociated with an operation, timing information specifying when toinitiate a task associated with an operation, data path informationspecifying what components to communicate with or access in carrying outan operation, and the like. Payload data, on the other hand, can includethe actual data involved in the storage operation, such as content datawritten to a secondary storage device 108 in a secondary copy operation.Payload metadata can include any of the types of metadata describedherein, and may be written to a storage device along with the payloadcontent data (e.g., in the form of a header).

In other embodiments, some information management operations arecontrolled by other components in the information management system 100(e.g., the media agent(s) 144 or data agent(s) 142), instead of or incombination with the storage manager 140.

According to certain embodiments, the storage manager 140 provides oneor more of the following functions:

-   -   initiating execution of secondary copy operations;    -   managing secondary storage devices 108 and inventory/capacity of        the same;    -   reporting, searching, and/or classification of data in the        information management system 100;    -   allocating secondary storage devices 108 for secondary storage        operations;    -   monitoring completion of and providing status reporting related        to secondary storage operations;    -   tracking age information relating to secondary copies 116,        secondary storage devices 108, and comparing the age information        against retention guidelines;    -   tracking movement of data within the information management        system 100;    -   tracking logical associations between components in the        information management system 100;    -   protecting metadata associated with the information management        system 100; and    -   implementing operations management functionality.

The storage manager 140 may maintain a database 146 (or “storage managerdatabase 146” or “management database 146”) of management-related dataand information management policies 148. The database 146 may include amanagement index 150 (or “index 150”) or other data structure thatstores logical associations between components of the system, userpreferences and/or profiles (e.g., preferences regarding encryption,compression, or deduplication of primary or secondary copy data,preferences regarding the scheduling, type, or other aspects of primaryor secondary copy or other operations, mappings of particularinformation management users or user accounts to certain computingdevices or other components, etc.), management tasks, mediacontainerization, or other useful data. For example, the storage manager140 may use the index 150 to track logical associations between mediaagents 144 and secondary storage devices 108 and/or movement of datafrom primary storage devices 104 to secondary storage devices 108. Forinstance, the index 150 may store data associating a client computingdevice 102 with a particular media agent 144 and/or secondary storagedevice 108, as specified in an information management policy 148 (e.g.,a storage policy, which is defined in more detail below).

Administrators and other employees may be able to manually configure andinitiate certain information management operations on an individualbasis. But while this may be acceptable for some recovery operations orother relatively less frequent tasks, it is often not workable forimplementing on-going organization-wide data protection and management.

Thus, the information management system 100 may utilize informationmanagement policies 148 for specifying and executing informationmanagement operations (e.g., on an automated basis). Generally, aninformation management policy 148 can include a data structure or otherinformation source that specifies a set of parameters (e.g., criteriaand rules) associated with storage or other information managementoperations.

The storage manager database 146 may maintain the information managementpolicies 148 and associated data, although the information managementpolicies 148 can be stored in any appropriate location. For instance, aninformation management policy 148 such as a storage policy may be storedas metadata in a media agent database 152 or in a secondary storagedevice 108 (e.g., as an archive copy) for use in restore operations orother information management operations, depending on the embodiment.Information management policies 148 are described further below.

According to certain embodiments, the storage manager database 146comprises a relational database (e.g., an SQL database) for trackingmetadata, such as metadata associated with secondary copy operations(e.g., what client computing devices 102 and corresponding data wereprotected). This and other metadata may additionally be stored in otherlocations, such as at the secondary storage computing devices 106 or onthe secondary storage devices 108, allowing data recovery without theuse of the storage manager 140.

As shown, the storage manager 140 may include a jobs agent 156, a userinterface 158, and a management agent 154, all of which may beimplemented as interconnected software modules or application programs.

The jobs agent 156 in some embodiments initiates, controls, and/ormonitors the status of some or all storage or other informationmanagement operations previously performed, currently being performed,or scheduled to be performed by the information management system 100.For instance, the jobs agent 156 may access information managementpolicies 148 to determine when and how to initiate and control secondarycopy and other information management operations, as will be discussedfurther.

The user interface 158 may include information processing and displaysoftware, such as a graphical user interface (“GUI”), an applicationprogram interface (“API”), or other interactive interface(s) throughwhich users and system processes can retrieve information about thestatus of information management operations (e.g., storage operations)or issue instructions to the information management system 100 and itsconstituent components.

Via the user interface 158, users may optionally issue instructions tothe components in the information management system 100 regardingperformance of storage and recovery operations. For example, a user maymodify a schedule concerning the number of pending secondary copyoperations. As another example, a user may employ the GUI to view thestatus of pending storage operations or to monitor the status of certaincomponents in the information management system 100 (e.g., the amount ofcapacity left in a storage device).

An information management “cell” may generally include a logical and/orphysical grouping of a combination of hardware and software componentsassociated with performing information management operations onelectronic data, typically one storage manager 140 and at least oneclient computing device 102 (comprising data agent(s) 142) and at leastone media agent 144. For instance, the components shown in FIG. 1C maytogether form an information management cell. Multiple cells may beorganized hierarchically. With this configuration, cells may inheritproperties from hierarchically superior cells or be controlled by othercells in the hierarchy (automatically or otherwise). Alternatively, insome embodiments, cells may inherit or otherwise be associated withinformation management policies, preferences, information managementmetrics, or other properties or characteristics according to theirrelative position in a hierarchy of cells. Cells may also be delineatedand/or organized hierarchically according to function, geography,architectural considerations, or other factors useful or desirable inperforming information management operations. A first cell may representa geographic segment of an enterprise, such as a Chicago office, and asecond cell may represent a different geographic segment, such as a NewYork office. Other cells may represent departments within a particularoffice. Where delineated by function, a first cell may perform one ormore first types of information management operations (e.g., one or morefirst types of secondary or other copies), and a second cell may performone or more second types of information management operations (e.g., oneor more second types of secondary or other copies).

The storage manager 140 may also track information that permits it toselect, designate, or otherwise identify content indices, deduplicationdatabases, or similar databases or resources or data sets within itsinformation management cell (or another cell) to be searched in responseto certain queries. Such queries may be entered by the user viainteraction with the user interface 158. In general, the managementagent 154 allows multiple information management cells to communicatewith one another. For example, the information management system 100 insome cases may be one information management cell of a network ofmultiple cells adjacent to one another or otherwise logically related ina WAN or LAN. With this arrangement, the cells may be connected to oneanother through respective management agents 154.

For instance, the management agent 154 can provide the storage manager140 with the ability to communicate with other components within theinformation management system 100 (and/or other cells within a largerinformation management system) via network protocols and applicationprogramming interfaces (“APIs”) including, e.g., HTTP, HTTPS, FTP, REST,virtualization software APIs, cloud service provider APIs, and hostedservice provider APIs. Inter-cell communication and hierarchy isdescribed in greater detail in U.S. Pat. Nos. 7,747,579 and 7,343,453,which are incorporated by reference herein.

Data Agents

As discussed, a variety of different types of applications 110 canreside on a given client computing device 102, including operatingsystems, database applications, e-mail applications, and virtualmachines, just to name a few. And, as part of the process of creatingand restoring secondary copies 116, the client computing devices 102 maybe tasked with processing and preparing the primary data 112 from thesevarious different applications 110. Moreover, the nature of theprocessing/preparation can differ across clients and application types,e.g., due to inherent structural and formatting differences betweenapplications 110.

The one or more data agent(s) 142 are therefore advantageouslyconfigured in some embodiments to assist in the performance ofinformation management operations based on the type of data that isbeing protected, at a client-specific and/or application-specific level.

The data agent 142 may be a software module or component that isgenerally responsible for managing, initiating, or otherwise assistingin the performance of information management operations. For instance,the data agent 142 may take part in performing data storage operationssuch as the copying, archiving, migrating, replicating of primary data112 stored in the primary storage device(s) 104. The data agent 142 mayreceive control information from the storage manager 140, such ascommands to transfer copies of data objects, metadata, and other payloaddata to the media agents 144.

In some embodiments, a data agent 142 may be distributed between theclient computing device 102 and storage manager 140 (and any otherintermediate components) or may be deployed from a remote location orits functions approximated by a remote process that performs some or allof the functions of data agent 142. In addition, a data agent 142 mayperform some functions provided by a media agent 144, or may performother functions such as encryption and deduplication.

As indicated, each data agent 142 may be specialized for a particularapplication 110, and the system can employ multiple application-specificdata agents 142, each of which may perform information managementoperations (e.g., perform backup, migration, and data recovery)associated with a different application 110. For instance, differentindividual data agents 142 may be designed to handle Microsoft Exchangedata, Lotus Notes data, Microsoft Windows file system data, MicrosoftActive Directory Objects data, SQL Server data, SharePoint data, Oracledatabase data, SAP database data, virtual machines and/or associateddata, and other types of data.

A file system data agent, for example, may handle data files and/orother file system information. If a client computing device 102 has twoor more types of data, one data agent 142 may be used for each data typeto copy, archive, migrate, and restore the client computing device 102data. For example, to backup, migrate, and restore all of the data on aMicrosoft Exchange server, the client computing device 102 may use oneMicrosoft Exchange Mailbox data agent 142 to backup the Exchangemailboxes, one Microsoft Exchange Database data agent 142 to backup theExchange databases, one Microsoft Exchange Public Folder data agent 142to backup the Exchange Public Folders, and one Microsoft Windows FileSystem data agent 142 to backup the file system of the client computingdevice 102. In such embodiments, these data agents 142 may be treated asfour separate data agents 142 even though they reside on the same clientcomputing device 102.

Other embodiments may employ one or more generic data agents 142 thatcan handle and process data from two or more different applications 110,or that can handle and process multiple data types, instead of or inaddition to using specialized data agents 142. For example, one genericdata agent 142 may be used to back up, migrate and restore MicrosoftExchange Mailbox data and Microsoft Exchange Database data while anothergeneric data agent may handle Microsoft Exchange Public Folder data andMicrosoft Windows File System data.

Each data agent 142 may be configured to access data and/or metadatastored in the primary storage device(s) 104 associated with the dataagent 142 and process the data as appropriate. For example, during asecondary copy operation, the data agent 142 may arrange or assemble thedata and metadata into one or more files having a certain format (e.g.,a particular backup or archive format) before transferring the file(s)to a media agent 144 or other component. The file(s) may include a listof files or other metadata. Each data agent 142 can also assist inrestoring data or metadata to primary storage devices 104 from asecondary copy 116. For instance, the data agent 142 may operate inconjunction with the storage manager 140 and one or more of the mediaagents 144 to restore data from secondary storage device(s) 108.

Media Agents

As indicated above with respect to FIG. 1A, off-loading certainresponsibilities from the client computing devices 102 to intermediatecomponents such as the media agent(s) 144 can provide a number ofbenefits including improved client computing device 102 operation,faster secondary copy operation performance, and enhanced scalability.As one specific example which will be discussed below in further detail,the media agent 144 can act as a local cache of copied data and/ormetadata that it has stored to the secondary storage device(s) 108,providing improved restore capabilities.

Generally speaking, a media agent 144 may be implemented as a softwaremodule that manages, coordinates, and facilitates the transmission ofdata, as directed by the storage manager 140, between a client computingdevice 102 and one or more secondary storage devices 108. Whereas thestorage manager 140 controls the operation of the information managementsystem 100, the media agent 144 generally provides a portal to secondarystorage devices 108. For instance, other components in the systeminteract with the media agents 144 to gain access to data stored on thesecondary storage devices 108, whether it be for the purposes ofreading, writing, modifying, or deleting data. Moreover, as will bedescribed further, media agents 144 can generate and store informationrelating to characteristics of the stored data and/or metadata, or cangenerate and store other types of information that generally providesinsight into the contents of the secondary storage devices 108.

Media agents 144 can comprise separate nodes in the informationmanagement system 100 (e.g., nodes that are separate from the clientcomputing devices 102, storage manager 140, and/or secondary storagedevices 108). In general, a node within the information managementsystem 100 can be a logically and/or physically separate component, andin some cases is a component that is individually addressable orotherwise identifiable. In addition, each media agent 144 may reside ona dedicated secondary storage computing device 106 in some cases, whilein other embodiments a plurality of media agents 144 reside on the samesecondary storage computing device 106.

A media agent 144 (and corresponding media agent database 152) may beconsidered to be “associated with” a particular secondary storage device108 if that media agent 144 is capable of one or more of: routing and/orstoring data to the particular secondary storage device 108,coordinating the routing and/or storing of data to the particularsecondary storage device 108, retrieving data from the particularsecondary storage device 108, coordinating the retrieval of data from aparticular secondary storage device 108, and modifying and/or deletingdata retrieved from the particular secondary storage device 108.

While media agent(s) 144 are generally associated with one or moresecondary storage devices 108, one or more media agents 144 in certainembodiments are physically separate from the secondary storage devices108. For instance, the media agents 144 may reside on secondary storagecomputing devices 106 having different housings or packages than thesecondary storage devices 108. In one example, a media agent 144 resideson a first server computer and is in communication with a secondarystorage device(s) 108 residing in a separate, rack-mounted RAID-basedsystem.

Where the information management system 100 includes multiple mediaagents 144 (FIG. 1D), a first media agent 144 may provide failoverfunctionality for a second, failed media agent 144. In addition, mediaagents 144 can be dynamically selected for storage operations to provideload balancing. Failover and load balancing are described in greaterdetail below.

In operation, a media agent 144 associated with a particular secondarystorage device 108 may instruct the secondary storage device 108 toperform an information management operation. For instance, a media agent144 may instruct a tape library to use a robotic arm or other retrievalmeans to load or eject a certain storage media, and to subsequentlyarchive, migrate, or retrieve data to or from that media, e.g., for thepurpose of restoring the data to a client computing device 102. Asanother example, a secondary storage device 108 may include an array ofhard disk drives or solid state drives organized in a RAIDconfiguration, and the media agent 144 may forward a logical unit number(LUN) and other appropriate information to the array, which uses thereceived information to execute the desired storage operation. The mediaagent 144 may communicate with a secondary storage device 108 via asuitable communications link, such as a SCSI or Fiber Channel link.

As shown, each media agent 144 may maintain an associated media agentdatabase 152. The media agent database 152 may be stored in a disk orother storage device (not shown) that is local to the secondary storagecomputing device 106 on which the media agent 144 resides. In othercases, the media agent database 152 is stored remotely from thesecondary storage computing device 106.

The media agent database 152 can include, among other things, an index153 including data generated during secondary copy operations and otherstorage or information management operations. The index 153 provides amedia agent 144 or other component with a fast and efficient mechanismfor locating secondary copies 116 or other data stored in the secondarystorage devices 108. In some cases, the index 153 does not form a partof and is instead separate from the media agent database 152.

A media agent index 153 or other data structure associated with theparticular media agent 144 may include information about the storeddata. For instance, for each secondary copy 116, the index 153 mayinclude metadata such as a list of the data objects (e.g.,files/subdirectories, database objects, mailbox objects, etc.), a pathto the secondary copy 116 on the corresponding secondary storage device108, location information indicating where the data objects are storedin the secondary storage device 108, when the data objects were createdor modified, etc. Thus, the index 153 includes metadata associated withthe secondary copies 116 that is readily available for use in storageoperations and other activities without having to be first retrievedfrom the secondary storage device 108. In yet further embodiments, someor all of the data in the index 153 may instead or additionally bestored along with the data in a secondary storage device 108, e.g., witha copy of the index 153. In some embodiments, the secondary storagedevices 108 can include sufficient information to perform a “bare metalrestore”, where the operating system of a failed client computing device102 or other restore target is automatically rebuilt as part of arestore operation.

Because the index 153 maintained in the media agent database 152 mayoperate as a cache, it can also be referred to as “an index cache.” Insuch cases, information stored in the index cache 153 typicallycomprises data that reflects certain particulars about storageoperations that have occurred relatively recently. After some triggeringevent, such as after a certain period of time elapses, or the indexcache 153 reaches a particular size, the index cache 153 may be copiedor migrated to a secondary storage device(s) 108. This information mayneed to be retrieved and uploaded back into the index cache 153 orotherwise restored to a media agent 144 to facilitate retrieval of datafrom the secondary storage device(s) 108. In some embodiments, thecached information may include format or containerization informationrelated to archives or other files stored on the storage device(s) 108.In this manner, the index cache 153 allows for accelerated restores.

In some alternative embodiments the media agent 144 generally acts as acoordinator or facilitator of storage operations between clientcomputing devices 102 and corresponding secondary storage devices 108,but does not actually write the data to the secondary storage device108. For instance, the storage manager 140 (or the media agent 144) mayinstruct a client computing device 102 and secondary storage device 108to communicate with one another directly. In such a case the clientcomputing device 102 transmits the data directly or via one or moreintermediary components to the secondary storage device 108 according tothe received instructions, and vice versa. In some such cases, the mediaagent 144 may still receive, process, and/or maintain metadata relatedto the storage operations. Moreover, in these embodiments, the payloaddata can flow through the media agent 144 for the purposes of populatingthe index cache 153 maintained in the media agent database 152, but notfor writing to the secondary storage device 108.

The media agent 144 and/or other components such as the storage manager140 may in some cases incorporate additional functionality, such as dataclassification, content indexing, deduplication, encryption,compression, and the like. Further details regarding these and otherfunctions are described below.

Distributed, Scalable Architecture

As described, certain functions of the information management system 100can be distributed amongst various physical and/or logical components inthe system. For instance, one or more of the storage manager 140, dataagents 142, and media agents 144 may reside on computing devices thatare physically separate from one another. This architecture can providea number of benefits.

For instance, hardware and software design choices for each distributedcomponent can be targeted to suit its particular function. The secondarycomputing devices 106 on which the media agents 144 reside can betailored for interaction with associated secondary storage devices 108and provide fast index cache operation, among other specific tasks.Similarly, the client computing device(s) 102 can be selected toeffectively service the applications 110 residing thereon, in order toefficiently produce and store primary data 112.

Moreover, in some cases, one or more of the individual components in theinformation management system 100 can be distributed to multiple,separate computing devices. As one example, for large file systems wherethe amount of data stored in the database 146 is relatively large, thedatabase 146 may be migrated to or otherwise reside on a specializeddatabase server (e.g., an SQL server) separate from a server thatimplements the other functions of the storage manager 140. Thisconfiguration can provide added protection because the database 146 canbe protected with standard database utilities (e.g., SQL log shipping ordatabase replication) independent from other functions of the storagemanager 140. The database 146 can be efficiently replicated to a remotesite for use in the event of a disaster or other data loss incident atthe primary site. Or the database 146 can be replicated to anothercomputing device within the same site, such as to a higher performancemachine in the event that a storage manager host device can no longerservice the needs of a growing information management system 100.

The distributed architecture also provides both scalability andefficient component utilization. FIG. 1D shows an embodiment of theinformation management system 100 including a plurality of clientcomputing devices 102 and associated data agents 142 as well as aplurality of secondary storage computing devices 106 and associatedmedia agents 144.

Additional components can be added or subtracted based on the evolvingneeds of the information management system 100. For instance, dependingon where bottlenecks are identified, administrators can add additionalclient computing devices 102, secondary storage computing devices 106(and corresponding media agents 144), and/or secondary storage devices108. Moreover, where multiple fungible components are available, loadbalancing can be implemented to dynamically address identifiedbottlenecks. As an example, the storage manager 140 may dynamicallyselect which media agents 144 and/or secondary storage devices 108 touse for storage operations based on a processing load analysis of themedia agents 144 and/or secondary storage devices 108, respectively.

Moreover, each client computing device 102 in some embodiments cancommunicate with, among other components, any of the media agents 144,e.g., as directed by the storage manager 140. And each media agent 144may be able to communicate with, among other components, any of thesecondary storage devices 108, e.g., as directed by the storage manager140. Thus, operations can be routed to the secondary storage devices 108in a dynamic and highly flexible manner, to provide load balancing,failover, and the like. Further examples of scalable systems capable ofdynamic storage operations, and of systems capable of performing loadbalancing and fail over are provided in U.S. Pat. No. 7,246,207, whichis incorporated by reference herein.

In alternative configurations, certain components are not distributedand may instead reside and execute on the same computing device. Forexample, in some embodiments one or more data agents 142 and the storagemanager 140 reside on the same client computing device 102. In anotherembodiment, one or more data agents 142 and one or more media agents 144reside on a single computing device.

Exemplary Types of Information Management Operations

In order to protect and leverage stored data, the information managementsystem 100 can be configured to perform a variety of informationmanagement operations. As will be described, these operations cangenerally include secondary copy and other data movement operations,processing and data manipulation operations, analysis, reporting, andmanagement operations. The operations described herein may be performedon any type of computing platform, e.g., between two computers connectedvia a LAN, to a mobile client telecommunications device connected to aserver via a WLAN, to any manner of client device coupled to a cloudstorage target.

Data Movement Operations

Data movement operations according to certain embodiments are generallyoperations that involve the copying or migration of data (e.g., payloaddata) between different locations in the information management system100 in an original/native and/or one or more different formats. Forexample, data movement operations can include operations in which storeddata is copied, migrated, or otherwise transferred from one or morefirst storage devices to one or more second storage devices, such asfrom primary storage device(s) 104 to secondary storage device(s) 108,from secondary storage device(s) 108 to different secondary storagedevice(s) 108, from secondary storage devices 108 to primary storagedevices 104, or from primary storage device(s) 104 to different primarystorage device(s) 104.

Data movement operations can include by way of example, backupoperations, archive operations, information lifecycle managementoperations such as hierarchical storage management operations,replication operations (e.g., continuous data replication operations),snapshot operations, deduplication or single-instancing operations,auxiliary copy operations, and the like. As will be discussed, some ofthese operations involve the copying, migration or other movement ofdata, without actually creating multiple, distinct copies. Nonetheless,some or all of these operations are referred to as “copy” operations forsimplicity.

Backup Operations

A backup operation creates a copy of a version of data (e.g., one ormore files or other data units) in primary data 112 at a particularpoint in time. Each subsequent backup copy may be maintainedindependently of the first. Further, a backup copy in some embodimentsis generally stored in a form that is different than the native format,e.g., a backup format. This can be in contrast to the version in primarydata 112 from which the backup copy is derived, and which may instead bestored in a native format of the source application(s) 110. In variouscases, backup copies can be stored in a format in which the data iscompressed, encrypted, deduplicated, and/or otherwise modified from theoriginal application format. For example, a backup copy may be stored ina backup format that facilitates compression and/or efficient long-termstorage.

Backup copies can have relatively long retention periods as compared toprimary data 112, and may be stored on media with slower retrieval timesthan primary data 112 and certain other types of secondary copies 116.On the other hand, backups may have relatively shorter retention periodsthan some other types of secondary copies 116, such as archive copies(described below). Backups may sometimes be stored at on offsitelocation.

Backup operations can include full, synthetic or incremental backups. Afull backup in some embodiments is generally a complete image of thedata to be protected. However, because full backup copies can consume arelatively large amount of storage, it can be useful to use a fullbackup copy as a baseline and only store changes relative to the fullbackup copy for subsequent backup copies.

For instance, a differential backup operation (or cumulative incrementalbackup operation) tracks and stores changes that have occurred since thelast full backup. Differential backups can grow quickly in size, but canprovide relatively efficient restore times because a restore can becompleted in some cases using only the full backup copy and the latestdifferential copy.

An incremental backup operation generally tracks and stores changessince the most recent backup copy of any type, which can greatly reducestorage utilization. In some cases, however, restore times can berelatively long in comparison to full or differential backups becausecompleting a restore operation may involve accessing a full backup inaddition to multiple incremental backups.

Any of the above types of backup operations can be at the volume-level,file-level, or block-level. Volume level backup operations generallyinvolve the copying of a data volume (e.g., a logical disk or partition)as a whole. In a file-level backup, the information management system100 may generally track changes to individual files at the file-level,and includes copies of files in the backup copy. In the case of ablock-level backup, files are broken into constituent blocks, andchanges are tracked at the block-level. Upon restore, the informationmanagement system 100 reassembles the blocks into files in a transparentfashion.

Far less data may actually be transferred and copied to the secondarystorage devices 108 during a file-level copy than a volume-level copy.Likewise, a block-level copy may involve the transfer of less data thana file-level copy, resulting in faster execution times. However,restoring a relatively higher-granularity copy can result in longerrestore times. For instance, when restoring a block-level copy, theprocess of locating constituent blocks can sometimes result in longerrestore times as compared to file-level backups. Similar to backupoperations, the other types of secondary copy operations describedherein can also be implemented at either the volume-level, file-level,or block-level.

Archive Operations

Because backup operations generally involve maintaining a version of thecopied data in primary data 112 and also maintaining backup copies insecondary storage device(s) 108, they can consume significant storagecapacity. To help reduce storage consumption, an archive operationaccording to certain embodiments creates a secondary copy 116 by bothcopying and removing source data. Or, seen another way, archiveoperations can involve moving some or all of the source data to thearchive destination. Thus, data satisfying criteria for removal (e.g.,data of a threshold age or size) from the source copy may be removedfrom source storage. Archive copies are sometimes stored in an archiveformat or other non-native application format. The source data may beprimary data 112 or a secondary copy 116, depending on the situation. Aswith backup copies, archive copies can be stored in a format in whichthe data is compressed, encrypted, deduplicated, and/or otherwisemodified from the original application format.

In addition, archive copies may be retained for relatively long periodsof time (e.g., years) and, in some cases, are never deleted. Archivecopies are generally retained for longer periods of time than backupcopies, for example. In certain embodiments, archive copies may be madeand kept for extended periods in order to meet compliance regulations.

Moreover, when primary data 112 is archived, in some cases the archivedprimary data 112 or a portion thereof is deleted when creating thearchive copy. Thus, archiving can serve the purpose of freeing up spacein the primary storage device(s) 104. Similarly, when a secondary copy116 is archived, the secondary copy 116 may be deleted, and an archivecopy can therefore serve the purpose of freeing up space in secondarystorage device(s) 108. In contrast, source copies often remain intactwhen creating backup copies. Examples of compatible data archivingoperations are provided in U.S. Pat. No. 7,107,298, which isincorporated by reference herein.

Snapshot Operations

Snapshot operations can provide a relatively lightweight, efficientmechanism for protecting data. From an end-user viewpoint, a snapshotmay be thought of as an “instant” image of the primary data 112 at agiven point in time, and may include state and/or status informationrelative to an application that creates/manages the data. In oneembodiment, a snapshot may generally capture the directory structure ofan object in primary data 112 such as a file or volume or other data setat a particular moment in time and may also preserve file attributes andcontents. A snapshot in some cases is created relatively quickly, e.g.,substantially instantly, using a minimum amount of file space, but maystill function as a conventional file system backup.

A “hardware snapshot” (or “hardware-based snapshot”) operation can be asnapshot operation where a target storage device (e.g., a primarystorage device 104 or a secondary storage device 108) performs thesnapshot operation in a self-contained fashion, substantiallyindependently, using hardware, firmware and/or software residing on thestorage device itself. For instance, the storage device may be capableof performing snapshot operations upon request, generally withoutintervention or oversight from any of the other components in theinformation management system 100. In this manner, In this manner,hardware snapshots can off-load other components of informationmanagement system 100 from processing involved in snapshot creation andmanagement.

A “software snapshot” (or “software-based snapshot”) operation, on theother hand, can be a snapshot operation in which one or more othercomponents in information management system 100 (e.g., client computingdevices 102, data agents 142, etc.) implement a software layer thatmanages the snapshot operation via interaction with the target storagedevice. For instance, the component implementing the snapshot managementsoftware layer may derive a set of pointers and/or data that representsthe snapshot. The snapshot management software layer may then transmitthe same to the target storage device, along with appropriateinstructions for writing the snapshot.

Some types of snapshots do not actually create another physical copy ofall the data as it existed at the particular point in time, but maysimply create pointers that are able to map files and directories tospecific memory locations (e.g., to specific disk blocks) where the dataresides, as it existed at the particular point in time. For example, asnapshot copy may include a set of pointers derived from the file systemor an application. In some other cases, the snapshot may be created atthe block-level, such as where creation of the snapshot occurs withoutawareness of the file system. Each pointer points to a respective storeddata block, so that collectively, the set of pointers reflect thestorage location and state of the data object (e.g., file(s) orvolume(s) or data set(s)) at a particular point in time when thesnapshot copy was created.

Once a snapshot has been taken, subsequent changes to the file systemtypically do not overwrite the blocks in use at the time of thesnapshot. Therefore, the initial snapshot may use only a small amount ofdisk space needed to record a mapping or other data structurerepresenting or otherwise tracking the blocks that correspond to thecurrent state of the file system. Additional disk space is usuallyrequired only when files and directories are actually later modified.Furthermore, when files are modified, typically only the pointers whichmap to blocks are copied, not the blocks themselves. In someembodiments, for example in the case of “copy-on-write” snapshots, whena block changes in primary storage, the block is copied to secondarystorage or cached in primary storage before the block is overwritten inprimary storage, and the pointer to that block changed to reflect thenew location of that block. The snapshot mapping of file system data mayalso be updated to reflect the changed block(s) at that particular pointin time. In some other cases, a snapshot includes a full physical copyof all or substantially all of the data represented by the snapshot.Further examples of snapshot operations are provided in U.S. Pat. No.7,529,782, which is incorporated by reference herein.

A snapshot copy in many cases can be made quickly and withoutsignificantly impacting primary computing resources because largeamounts of data need not be copied or moved. In some embodiments, asnapshot may exist as a virtual file system, parallel to the actual filesystem. Users in some cases gain read-only access to the record of filesand directories of the snapshot. By electing to restore primary data 112from a snapshot taken at a given point in time, users may also returnthe current file system to the state of the file system that existedwhen the snapshot was taken.

Replication Operations

Another type of secondary copy operation is a replication operation.Some types of secondary copies 116 are used to periodically captureimages of primary data 112 at particular points in time (e.g., backups,archives, and snapshots). However, it can also be useful for recoverypurposes to protect primary data 112 in a more continuous fashion, byreplicating the primary data 112 substantially as changes occur. In somecases a replication copy can be a mirror copy, for instance, wherechanges made to primary data 112 are mirrored or substantiallyimmediately copied to another location (e.g., to secondary storagedevice(s) 108). By copying each write operation to the replication copy,two storage systems are kept synchronized or substantially synchronizedso that they are virtually identical at approximately the same time.Where entire disk volumes are mirrored, however, mirroring can requiresignificant amount of storage space and utilizes a large amount ofprocessing resources.

According to some embodiments storage operations are performed onreplicated data that represents a recoverable state, or “known goodstate” of a particular application running on the source system. Forinstance, in certain embodiments, known good replication copies may beviewed as copies of primary data 112. This feature allows the system todirectly access, copy, restore, backup or otherwise manipulate thereplication copies as if the data was the “live”, primary data 112. Thiscan reduce access time, storage utilization, and impact on sourceapplications 110, among other benefits.

Based on known good state information, the information management system100 can replicate sections of application data that represent arecoverable state rather than rote copying of blocks of data. Examplesof compatible replication operations (e.g., continuous data replication)are provided in U.S. Pat. No. 7,617,262, which is incorporated byreference herein.

Deduplication/Single-Instancing Operations

Another type of data movement operation is deduplication orsingle-instance storage, which is useful to reduce the amount of datawithin the system. For instance, some or all of the above-describedsecondary storage operations can involve deduplication in some fashion.New data is read, broken down into portions (e.g., sub-file levelblocks, files, etc.) of a selected granularity, compared with blocksthat are already stored, and only the new blocks are stored. Blocks thatalready exist are represented as pointers to the already stored data.

In order to streamline the comparison process, the informationmanagement system 100 may calculate and/or store signatures (e.g.,hashes or cryptographically unique IDs) corresponding to the individualdata blocks in a database and compare the signatures instead ofcomparing entire data blocks. In some cases, only a single instance ofeach element is stored, and deduplication operations may therefore bereferred to interchangeably as “single-instancing” operations. Dependingon the implementation, however, deduplication or single-instancingoperations can store more than one instance of certain data blocks, butnonetheless significantly reduce data redundancy.

Depending on the embodiment, deduplication blocks can be of fixed orvariable length. Using variable length blocks can provide enhanceddeduplication by responding to changes in the data stream, but caninvolve complex processing. In some cases, the information managementsystem 100 utilizes a technique for dynamically aligning deduplicationblocks (e.g., fixed-length blocks) based on changing content in the datastream, as described in U.S. Pat. No. 8,364,652, which is incorporatedby reference herein.

The information management system 100 can perform deduplication in avariety of manners at a variety of locations in the informationmanagement system 100. For instance, in some embodiments, theinformation management system 100 implements “target-side” deduplicationby deduplicating data (e.g., secondary copies 116) stored in thesecondary storage devices 108. In some such cases, the media agents 144are generally configured to manage the deduplication process. Forinstance, one or more of the media agents 144 maintain a correspondingdeduplication database that stores deduplication information (e.g.,datablock signatures). Examples of such a configuration are provided inU.S. Pat. Pub. No. 2012/0150826, which is incorporated by referenceherein. Instead of or in combination with “target-side” deduplication,deduplication can also be performed on the “source-side” (or“client-side”), e.g., to reduce the amount of traffic between the mediaagents 144 and the client computing device(s) 102 and/or reduceredundant data stored in the primary storage devices 104. According tovarious implementations, one or more of the storage devices of thetarget-side, source-side, or client-side of an operation can becloud-based storage devices. Thus, the target-side, source-side, and/orclient-side deduplication can be cloud-based deduplication. Inparticular, as discussed previously, the storage manager 140 maycommunicate with other components within the information managementsystem 100 via network protocols and cloud service provider APIs tofacilitate cloud-based deduplication/single instancing. Examples of suchdeduplication techniques are provided in U.S. Pat. Pub. No.2012/0150818, which is incorporated by reference herein. Some othercompatible deduplication/single instancing techniques are described inU.S. Pat. Pub. Nos. 2006/0224846 and 2009/0319534, which areincorporated by reference herein.

Information Lifecycle Management and Hierarchical Storage ManagementOperations

In some embodiments, files and other data over their lifetime move frommore expensive, quick access storage to less expensive, slower accessstorage. Operations associated with moving data through various tiers ofstorage are sometimes referred to as information lifecycle management(ILM) operations.

One type of ILM operation is a hierarchical storage management (HSM)operation. A HSM operation is generally an operation for automaticallymoving data between classes of storage devices, such as betweenhigh-cost and low-cost storage devices. For instance, an HSM operationmay involve movement of data from primary storage devices 104 tosecondary storage devices 108, or between tiers of secondary storagedevices 108. With each tier, the storage devices may be progressivelyrelatively cheaper, have relatively slower access/restore times, etc.For example, movement of data between tiers may occur as data becomesless important over time.

In some embodiments, an HSM operation is similar to an archive operationin that creating an HSM copy may (though not always) involve deletingsome of the source data, e.g., according to one or more criteria relatedto the source data. For example, an HSM copy may include data fromprimary data 112 or a secondary copy 116 that is larger than a givensize threshold or older than a given age threshold and that is stored ina backup format.

Often, and unlike some types of archive copies, HSM data that is removedor aged from the source copy is replaced by a logical reference pointeror stub. The reference pointer or stub can be stored in the primarystorage device 104 (or other source storage device, such as a secondarystorage device 108) to replace the deleted data in primary data 112 (orother source copy) and to point to or otherwise indicate the newlocation in a secondary storage device 108.

According to one example, files are generally moved between higher andlower cost storage depending on how often the files are accessed. When auser requests access to the HSM data that has been removed or migrated,the information management system 100 uses the stub to locate the dataand often make recovery of the data appear transparent, even though theHSM data may be stored at a location different from the remaining sourcedata. In this manner, the data appears to the user (e.g., in file systembrowsing windows and the like) as if it still resides in the sourcelocation (e.g., in a primary storage device 104). The stub may alsoinclude some metadata associated with the corresponding data, so that afile system and/or application can provide some information about thedata object and/or a limited-functionality version (e.g., a preview) ofthe data object.

An HSM copy may be stored in a format other than the native applicationformat (e.g., where the data is compressed, encrypted, deduplicated,and/or otherwise modified from the original application format). In somecases, copies which involve the removal of data from source storage andthe maintenance of stub or other logical reference information on sourcestorage may be referred to generally as “online archive copies”. On theother hand, copies which involve the removal of data from source storagewithout the maintenance of stub or other logical reference informationon source storage may be referred to as “off-line archive copies”.Examples of HSM and ILM techniques are provided in U.S. Pat. No.7,343,453, which is incorporated by reference herein.

Auxiliary Copy and Disaster Recovery Operations

An auxiliary copy is generally a copy operation in which a copy iscreated of an existing secondary copy 116. For instance, an initialsecondary copy 116 may be generated using or otherwise be derived fromprimary data 112 (or other data residing in the secondary storagesubsystem 118), whereas an auxiliary copy is generated from the initialsecondary copy 116. Auxiliary copies can be used to create additionalstandby copies of data and may reside on different secondary storagedevices 108 than the initial secondary copies 116. Thus, auxiliarycopies can be used for recovery purposes if initial secondary copies 116become unavailable. Exemplary compatible auxiliary copy techniques aredescribed in further detail in U.S. Pat. No. 8,230,195, which isincorporated by reference herein.

The information management system 100 may also perform disaster recoveryoperations that make or retain disaster recovery copies, often assecondary, high-availability disk copies. The information managementsystem 100 may create secondary disk copies and store the copies atdisaster recovery locations using auxiliary copy or replicationoperations, such as continuous data replication technologies. Dependingon the particular data protection goals, disaster recovery locations canbe remote from the client computing devices 102 and primary storagedevices 104, remote from some or all of the secondary storage devices108, or both.

Data Analysis, Reporting, and Management Operations

Data analysis, reporting, and management operations can be differentthan data movement operations in that they do not necessarily involvethe copying, migration or other transfer of data (e.g., primary data 112or secondary copies 116) between different locations in the system. Forinstance, data analysis operations may involve processing (e.g., offlineprocessing) or modification of already stored primary data 112 and/orsecondary copies 116. However, in some embodiments data analysisoperations are performed in conjunction with data movement operations.Some data analysis operations include content indexing operations andclassification operations which can be useful in leveraging the dataunder management to provide enhanced search and other features. Otherdata analysis operations such as compression and encryption can providedata reduction and security benefits, respectively.

Classification Operations/Content Indexing

In some embodiments, the information management system 100 analyzes andindexes characteristics, content, and metadata associated with the datastored within the primary data 112 and/or secondary copies 116,providing enhanced search and management capabilities for data discoveryand other purposes. The content indexing can be used to identify filesor other data objects having pre-defined content (e.g., user-definedkeywords or phrases, other keywords/phrases that are not defined by auser, etc.), and/or metadata (e.g., email metadata such as “to”, “from”,“cc”, “bcc”, attachment name, received time, etc.).

The information management system 100 generally organizes and cataloguesthe results in a content index, which may be stored within the mediaagent database 152, for example. The content index can also include thestorage locations of (or pointer references to) the indexed data in theprimary data 112 or secondary copies 116, as appropriate. The resultsmay also be stored, in the form of a content index database orotherwise, elsewhere in the information management system 100 (e.g., inthe primary storage devices 104, or in the secondary storage device108). Such index data provides the storage manager 140 or anothercomponent with an efficient mechanism for locating primary data 112and/or secondary copies 116 of data objects that match particularcriteria.

For instance, search criteria can be specified by a user through userinterface 158 of the storage manager 140. In some cases, the informationmanagement system 100 analyzes data and/or metadata in secondary copies116 to create an “off-line” content index, without significantlyimpacting the performance of the client computing devices 102. Dependingon the embodiment, the system can also implement “on-line” contentindexing, e.g., of primary data 112. Examples of compatible contentindexing techniques are provided in U.S. Pat. No. 8,170,995, which isincorporated by reference herein.

In order to further leverage the data stored in the informationmanagement system 100 to perform these and other tasks, one or morecomponents can be configured to scan data and/or associated metadata forclassification purposes to populate a database (or other data structure)of information (which can be referred to as a “data classificationdatabase” or a “metabase”). Depending on the embodiment, the dataclassification database(s) can be organized in a variety of differentways, including centralization, logical sub-divisions, and/or physicalsub-divisions. For instance, one or more centralized data classificationdatabases may be associated with different subsystems or tiers withinthe information management system 100. As an example, there may be afirst centralized metabase associated with the primary storage subsystem117 and a second centralized metabase associated with the secondarystorage subsystem 118. In other cases, there may be one or moremetabases associated with individual components. For instance, there maybe a dedicated metabase associated with some or all of the clientcomputing devices 102 and/or media agents 144. In some embodiments, adata classification database may reside as one or more data structureswithin management database 146, or may be otherwise associated withstorage manager 140.

In some cases, the metabase(s) may be included in separate database(s)and/or on separate storage device(s) from primary data 112 and/orsecondary copies 116, such that operations related to the metabase donot significantly impact performance on other components in theinformation management system 100. In other cases, the metabase(s) maybe stored along with primary data 112 and/or secondary copies 116. Filesor other data objects can be associated with identifiers (e.g., tagentries, etc.) in the media agent 144 (or other indices) to facilitatesearches of stored data objects. Among a number of other benefits, themetabase can also allow efficient, automatic identification of files orother data objects to associate with secondary copy or other informationmanagement operations (e.g., in lieu of scanning an entire file system).Examples of compatible metabases and data classification operations areprovided in U.S. Pat. Nos. 8,229,954 and 7,747,579, which areincorporated by reference herein.

Encryption Operations

The information management system 100 in some cases is configured toprocess data (e.g., files or other data objects, secondary copies 116,etc.), according to an appropriate encryption algorithm (e.g., Blowfish,Advanced Encryption Standard [AES], Triple Data Encryption Standard[3-DES], etc.) to limit access and provide data security in theinformation management system 100.

The information management system 100 in some cases encrypts the data atthe client level, such that the client computing devices 102 (e.g., thedata agents 142) encrypt the data prior to forwarding the data to othercomponents, e.g., before sending the data to media agents 144 during asecondary copy operation. In such cases, the client computing device 102may maintain or have access to an encryption key or passphrase fordecrypting the data upon restore. Encryption can also occur whencreating copies of secondary copies, e.g., when creating auxiliarycopies or archive copies. In yet further embodiments, the secondarystorage devices 108 can implement built-in, high performance hardwareencryption.

Management and Reporting Operations

Certain embodiments leverage the integrated, ubiquitous nature of theinformation management system 100 to provide useful system-widemanagement and reporting functions. Examples of some compatiblemanagement and reporting techniques are provided in U.S. Pat. No.7,343,453, which is incorporated by reference herein.

Operations management can generally include monitoring and managing thehealth and performance of information management system 100 by, withoutlimitation, performing error tracking, generating granularstorage/performance metrics (e.g., job success/failure information,deduplication efficiency, etc.), generating storage modeling and costinginformation, and the like.

As an example, a storage manager 140 or other component in theinformation management system 100 may analyze traffic patterns andsuggest or automatically route data via a particular route to e.g.,certain facilitate storage and minimize congestion. In some embodiments,the system can generate predictions relating to storage operations orstorage operation information. Such predictions described may be basedon a trending analysis that may be used to predict various networkoperations or use of network resources such as network traffic levels,storage media use, use of bandwidth of communication links, use of mediaagent components, etc. Further examples of traffic analysis, trendanalysis, prediction generation, and the like are described in U.S. Pat.No. 7,343,453, which is incorporated by reference herein.

In some configurations, a master storage manager 140 may track thestatus of a set of associated storage operation cells in a hierarchy ofinformation management cells, such as the status of jobs, systemcomponents, system resources, and other items, by communicating withstorage managers 140 (or other components) in the respective storageoperation cells. Moreover, the master storage manager 140 may track thestatus of its associated storage operation cells and associatedinformation management operations by receiving periodic status updatesfrom the storage managers 140 (or other components) in the respectivecells regarding jobs, system components, system resources, and otheritems. In some embodiments, a master storage manager 140 may storestatus information and other information regarding its associatedstorage operation cells and other system information in its index 150(or other location).

The master storage manager 140 or other component in the system may alsodetermine whether a storage-related criteria or other criteria issatisfied, and perform an action or trigger event (e.g., data migration)in response to the criteria being satisfied, such as where a storagethreshold is met for a particular volume, or where inadequate protectionexists for certain data. For instance, in some embodiments, the systemuses data from one or more storage operation cells to advise users ofrisks or indicates actions that can be used to mitigate or otherwiseminimize these risks, and in some embodiments, dynamically takes actionto mitigate or minimize these risks. For example, an informationmanagement policy may specify certain requirements (e.g., that a storagedevice should maintain a certain amount of free space, that secondarycopies should occur at a particular interval, that data should be agedand migrated to other storage after a particular period, that data on asecondary volume should always have a certain level of availability andbe able to be restored within a given time period, that data on asecondary volume may be mirrored or otherwise migrated to a specifiednumber of other volumes, etc.). If a risk condition or other criteria istriggered, the system can notify the user of these conditions and maysuggest (or automatically implement) an action to mitigate or otherwiseaddress the condition or minimize risk. For example, the system mayindicate that data from a primary copy 112 should be migrated to asecondary storage device 108 to free space on the primary storage device104. Examples of the use of risk factors and other triggering criteriaare described in U.S. Pat. No. 7,343,453, which is incorporated byreference herein.

In some embodiments, the system 100 may also determine whether a metricor other indication satisfies a particular storage criteria and, if so,perform an action. For example, as previously described, a storagepolicy or other definition might indicate that a storage manager 140should initiate a particular action if a storage metric or otherindication drops below or otherwise fails to satisfy specified criteriasuch as a threshold of data protection. Examples of such metrics aredescribed in U.S. Pat. No. 7,343,453, which is incorporated by referenceherein.

In some embodiments, risk factors may be quantified into certainmeasurable service or risk levels for ease of comprehension. Forexample, certain applications and associated data may be considered tobe more important by an enterprise than other data and services,Financial compliance data, for example, may be of greater importancethan marketing materials, etc. Network administrators may assignpriorities or “weights” to certain data or applications, correspondingto its importance (priority value). The level of compliance with thestorage operations specified for these applications may also be assigneda certain value. Thus, the health, impact and overall importance of aservice on an enterprise may be determined, for example, by measuringthe compliance value and calculating the product of the priority valueand the compliance value to determine the “service level” and comparingit to certain operational thresholds to determine if the operation isbeing performed within a specified data protection service level.Further examples of the service level determination are provided in U.S.Pat. No. 7,343,453, which is incorporated by reference herein.

The system 100 may additionally calculate data costing and dataavailability associated with information management operation cellsaccording to an embodiment of the invention. For instance, data receivedfrom the cell may be used in conjunction with hardware-relatedinformation and other information about network elements to generateindications of costs associated with storage of particular data in thesystem or the availability of particular data in the system. In general,components in the system are identified and associated information isobtained (dynamically or manually). Characteristics or metricsassociated with the network elements may be identified and associatedwith that component element for further use generating an indication ofstorage cost or data availability. Exemplary information generated couldinclude how fast a particular department is using up available storagespace, how long data would take to recover over a particular networkpathway from a particular secondary storage device, costs over time,etc. Moreover, in some embodiments, such information may be used todetermine or predict the overall cost associated with the storage ofcertain information. The cost associated with hosting a certainapplication may be based, at least in part, on the type of media onwhich the data resides. Storage devices may be assigned to a particularcost category which is indicative of the cost of storing information onthat device. Further examples of costing techniques are described inU.S. Pat. No. 7,343,453, which is incorporated by reference herein.

Any of the above types of information (e.g., information related totrending, predictions, job, cell or component status, risk, servicelevel, costing, etc.) can generally be provided to users via the userinterface 158 in a single, integrated view or console. The console maysupport a reporting capability that allows for the generation of avariety of reports, which may be tailored to a particular aspect ofinformation management. Report types may include: scheduling, eventmanagement, media management and data aging. Available reports may alsoinclude backup history, data aging history, auxiliary copy history, jobhistory, library and drive, media in library, restore history, andstorage policy. Such reports may be specified and created at a certainpoint in time as a network analysis, forecasting, or provisioning tool.Integrated reports may also be generated that illustrate storage andperformance metrics, risks and storage costing information. Moreover,users may create their own reports based on specific needs.

The integrated user interface 158 can include an option to show a“virtual view” of the system that graphically depicts the variouscomponents in the system using appropriate icons. As one example, theuser interface 158 may provide a graphical depiction of one or moreprimary storage devices 104, the secondary storage devices 108, dataagents 142 and/or media agents 144, and their relationship to oneanother in the information management system 100. The operationsmanagement functionality can facilitate planning and decision-making.For example, in some embodiments, a user may view the status of some orall jobs as well as the status of each component of the informationmanagement system 100. Users may then plan and make decisions based onthis data. For instance, a user may view high-level informationregarding storage operations for the information management system 100,such as job status, component status, resource status (e.g., networkpathways, etc.), and other information. The user may also drill down oruse other means to obtain more detailed information regarding aparticular component, job, or the like.

Further examples of some reporting techniques and associated interfacesproviding an integrated view of an information management system areprovided in U.S. Pat. No. 7,343,453, which is incorporated by referenceherein.

The information management system 100 can also be configured to performsystem-wide e-discovery operations in some embodiments. In general,e-discovery operations provide a unified collection and searchcapability for data in the system, such as data stored in the secondarystorage devices 108 (e.g., backups, archives, or other secondary copies116). For example, the information management system 100 may constructand maintain a virtual repository for data stored in the informationmanagement system 100 that is integrated across source applications 110,different storage device types, etc. According to some embodiments,e-discovery utilizes other techniques described herein, such as dataclassification and/or content indexing.

Information Management Policies

As indicated previously, an information management policy 148 caninclude a data structure or other information source that specifies aset of parameters (e.g., criteria and rules) associated with secondarycopy or other information management operations.

One type of information management policy 148 is a storage policy.According to certain embodiments, a storage policy generally comprises adata structure or other information source that defines (or includesinformation sufficient to determine) a set of preferences or othercriteria for performing information management operations. Storagepolicies can include one or more of the following items: (1) what datawill be associated with the storage policy; (2) a destination to whichthe data will be stored; (3) datapath information specifying how thedata will be communicated to the destination; (4) the type of storageoperation to be performed; and (5) retention information specifying howlong the data will be retained at the destination.

As an illustrative example, data associated with a storage policy can belogically organized into groups. In some cases, these logical groupingscan be referred to as “sub-clients”. A sub-client may represent staticor dynamic associations of portions of a data volume. Sub-clients mayrepresent mutually exclusive portions. Thus, in certain embodiments, aportion of data may be given a label and the association is stored as astatic entity in an index, database or other storage location.

Sub-clients may also be used as an effective administrative scheme oforganizing data according to data type, department within theenterprise, storage preferences, or the like. Depending on theconfiguration, sub-clients can correspond to files, folders, virtualmachines, databases, etc. In one exemplary scenario, an administratormay find it preferable to separate e-mail data from financial data usingtwo different sub-clients.

A storage policy can define where data is stored by specifying a targetor destination storage device (or group of storage devices). Forinstance, where the secondary storage device 108 includes a group ofdisk libraries, the storage policy may specify a particular disk libraryfor storing the sub-clients associated with the policy. As anotherexample, where the secondary storage devices 108 include one or moretape libraries, the storage policy may specify a particular tape libraryfor storing the sub-clients associated with the storage policy, and mayalso specify a drive pool and a tape pool defining a group of tapedrives and a group of tapes, respectively, for use in storing thesub-client data. While information in the storage policy can bestatically assigned in some cases, some or all of the information in thestorage policy can also be dynamically determined based on criteria,which can be set forth in the storage policy. For instance, based onsuch criteria, a particular destination storage device(s) (or otherparameter of the storage policy) may be determined based oncharacteristics associated with the data involved in a particularstorage operation, device availability (e.g., availability of asecondary storage device 108 or a media agent 144), network status andconditions (e.g., identified bottlenecks), user credentials, and thelike).

Datapath information can also be included in the storage policy. Forinstance, the storage policy may specify network pathways and componentsto utilize when moving the data to the destination storage device(s). Insome embodiments, the storage policy specifies one or more media agents144 for conveying data (e.g., one or more sub-clients) associated withthe storage policy between the source (e.g., one or more host clientcomputing devices 102) and destination (e.g., a particular targetsecondary storage device 108).

A storage policy can also specify the type(s) of operations associatedwith the storage policy, such as a backup, archive, snapshot, auxiliarycopy, or the like. Retention information can specify how long the datawill be kept, depending on organizational needs (e.g., a number of days,months, years, etc.)

The information management policies 148 may also include one or morescheduling policies specifying when and how often to perform operations.Scheduling information may specify with what frequency (e.g., hourly,weekly, daily, event-based, etc.) or under what triggering conditionssecondary copy or other information management operations will takeplace. Scheduling policies in some cases are associated with particularcomponents, such as particular logical groupings of data associated witha storage policy (e.g., a sub-client), client computing device 102, andthe like. In one configuration, a separate scheduling policy ismaintained for particular logical groupings of data on a clientcomputing device 102. The scheduling policy specifies that those logicalgroupings are to be moved to secondary storage devices 108 every houraccording to storage policies associated with the respectivesub-clients.

When adding a new client computing device 102, administrators canmanually configure information management policies 148 and/or othersettings, e.g., via the user interface 158. However, this can be aninvolved process resulting in delays, and it may be desirable to begindata protecting operations quickly.

Thus, in some embodiments, the information management system 100automatically applies a default configuration to client computing device102. As one example, when one or more data agent(s) 142 are installed onone or more client computing devices 102, the installation script mayregister the client computing device 102 with the storage manager 140,which in turn applies the default configuration to the new clientcomputing device 102. In this manner, data protection operations canbegin substantially immediately. The default configuration can include adefault storage policy, for example, and can specify any appropriateinformation sufficient to begin data protection operations. This caninclude a type of data protection operation, scheduling information, atarget secondary storage device 108, data path information (e.g., aparticular media agent 144), and the like.

Other types of information management policies 148 are possible. Forinstance, the information management policies 148 can also include oneor more audit or security policies. An audit policy is a set ofpreferences, rules and/or criteria that protect sensitive data in theinformation management system 100. For example, an audit policy maydefine “sensitive objects” as files or objects that contain particularkeywords (e.g., “confidential,” or “privileged”) and/or are associatedwith particular keywords (e.g., in metadata) or particular flags (e.g.,in metadata identifying a document or email as personal, confidential,etc.).

An audit policy may further specify rules for handling sensitiveobjects. As an example, an audit policy may require that a reviewerapprove the transfer of any sensitive objects to a cloud storage site,and that if approval is denied for a particular sensitive object, thesensitive object should be transferred to a local primary storage device104 instead. To facilitate this approval, the audit policy may furtherspecify how a secondary storage computing device 106 or other systemcomponent should notify a reviewer that a sensitive object is slated fortransfer.

In some implementations, the information management policies 148 mayinclude one or more provisioning policies. A provisioning policy caninclude a set of preferences, priorities, rules, and/or criteria thatspecify how client computing devices 102 (or groups thereof) may utilizesystem resources, such as available storage on cloud storage and/ornetwork bandwidth. A provisioning policy specifies, for example, dataquotas for particular client computing devices 102 (e.g., a number ofgigabytes that can be stored monthly, quarterly or annually). Thestorage manager 140 or other components may enforce the provisioningpolicy. For instance, the media agents 144 may enforce the policy whentransferring data to secondary storage devices 108. If a clientcomputing device 102 exceeds a quota, a budget for the client computingdevice 102 (or associated department) is adjusted accordingly or analert may trigger.

While the above types of information management policies 148 have beendescribed as separate policies, one or more of these can be generallycombined into a single information management policy 148. For instance,a storage policy may also include or otherwise be associated with one ormore scheduling, audit, or provisioning policies. Moreover, whilestorage policies are typically associated with moving and storing data,other policies may be associated with other types of informationmanagement operations. The following is a non-exhaustive list of itemsthe information management policies 148 may specify:

-   -   schedules or other timing information, e.g., specifying when        and/or how often to perform information management operations;    -   the type of copy 116 (e.g., type of secondary copy) and/or copy        format (e.g., snapshot, backup, archive, HSM, etc.);    -   a location or a class or quality of storage for storing        secondary copies 116 (e.g., one or more particular secondary        storage devices 108);    -   preferences regarding whether and how to encrypt, compress,        deduplicate, or otherwise modify or transform secondary copies        116;    -   which system components and/or network pathways (e.g., preferred        media agents 144) should be used to perform secondary storage        operations;    -   resource allocation between different computing devices or other        system components used in performing information management        operations (e.g., bandwidth allocation, available storage        capacity, etc.);    -   whether and how to synchronize or otherwise distribute files or        other data objects across multiple computing devices or hosted        services; and    -   retention information specifying the length of time primary data        112 and/or secondary copies 116 should be retained, e.g., in a        particular class or tier of storage devices, or within the        information management system 100.

Policies can additionally specify or depend on a variety of historicalor current criteria that may be used to determine which rules to applyto a particular data object, system component, or information managementoperation, such as:

-   -   frequency with which primary data 112 or a secondary copy 116 of        a data object or metadata has been or is predicted to be used,        accessed, or modified;    -   time-related factors (e.g., aging information such as time since        the creation or modification of a data object);    -   deduplication information (e.g., hashes, data blocks,        deduplication block size, deduplication efficiency or other        metrics);    -   an estimated or historic usage or cost associated with different        components (e.g., with secondary storage devices 108);    -   the identity of users, applications 110, client computing        devices 102 and/or other computing devices that created,        accessed, modified, or otherwise utilized primary data 112 or        secondary copies 116;    -   a relative sensitivity (e.g., confidentiality) of a data object,        e.g., as determined by its content and/or metadata;    -   the current or historical storage capacity of various storage        devices;    -   the current or historical network capacity of network pathways        connecting various components within the storage operation cell;    -   access control lists or other security information; and    -   the content of a particular data object (e.g., its textual        content) or of metadata associated with the data object.        Exemplary Storage Policy and Secondary Storage Operations

FIG. 1E shows a data flow data diagram depicting performance of storageoperations by an embodiment of an information management system 100,according to an exemplary storage policy 148A. The informationmanagement system 100 includes a storage manger 140, a client computingdevice 102 having a file system data agent 142A and an email data agent142B residing thereon, a primary storage device 104, two media agents144A, 144B, and two secondary storage devices 108A, 108B: a disk library108A and a tape library 108B. As shown, the primary storage device 104includes primary data 112A, 112B associated with a logical grouping ofdata associated with a file system) and a logical grouping of dataassociated with email data, respectively. Although for simplicity thelogical grouping of data associated with the file system is referred toas a file system sub-client, and the logical grouping of data associatedwith the email data is referred to as an email sub-client, thetechniques described with respect to FIG. 1E can be utilized inconjunction with data that is organized in a variety of other manners.

As indicated by the dashed box, the second media agent 144B and the tapelibrary 108B are “off-site”, and may therefore be remotely located fromthe other components in the information management system 100 (e.g., ina different city, office building, etc.). Indeed, “off-site” may referto a magnetic tape located in storage, which must be manually retrievedand loaded into a tape drive to be read. In this manner, informationstored on the tape library 108B may provide protection in the event of adisaster or other failure.

The file system sub-client and its associated primary data 112A incertain embodiments generally comprise information generated by the filesystem and/or operating system of the client computing device 102, andcan include, for example, file system data (e.g., regular files, filetables, mount points, etc.), operating system data (e.g., registries,event logs, etc.), and the like. The e-mail sub-client, on the otherhand, and its associated primary data 112B, include data generated by ane-mail client application operating on the client computing device 102,and can include mailbox information, folder information, emails,attachments, associated database information, and the like. As describedabove, the sub-clients can be logical containers, and the data includedin the corresponding primary data 112A, 112B may or may not be storedcontiguously.

The exemplary storage policy 148A includes backup copy preferences orrule set 160, disaster recovery copy preferences rule set 162, andcompliance copy preferences or rule set 164. The backup copy rule set160 specifies that it is associated with a file system sub-client 166and an email sub-client 168. Each of these sub-clients 166, 168 areassociated with the particular client computing device 102. The backupcopy rule set 160 further specifies that the backup operation will bewritten to the disk library 108A, and designates a particular mediaagent 144A to convey the data to the disk library 108A. Finally, thebackup copy rule set 160 specifies that backup copies created accordingto the rule set 160 are scheduled to be generated on an hourly basis andto be retained for 30 days. In some other embodiments, schedulinginformation is not included in the storage policy 148A, and is insteadspecified by a separate scheduling policy.

The disaster recovery copy rule set 162 is associated with the same twosub-clients 166, 168. However, the disaster recovery copy rule set 162is associated with the tape library 108B, unlike the backup copy ruleset 160. Moreover, the disaster recovery copy rule set 162 specifiesthat a different media agent 144B than the media agent 144A associatedwith the backup copy rule set 160 will be used to convey the data to thetape library 108B. As indicated, disaster recovery copies createdaccording to the rule set 162 will be retained for 60 days, and will begenerated on a daily basis. Disaster recovery copies generated accordingto the disaster recovery copy rule set 162 can provide protection in theevent of a disaster or other data-loss event that would affect thebackup copy 116A maintained on the disk library 108A.

The compliance copy rule set 164 is only associated with the emailsub-client 168, and not the file system sub-client 166. Compliancecopies generated according to the compliance copy rule set 164 willtherefore not include primary data 112A from the file system sub-client166. For instance, the organization may be under an obligation to storeand maintain copies of email data for a particular period of time (e.g.,10 years) to comply with state or federal regulations, while similarregulations do not apply to the file system data. The compliance copyrule set 164 is associated with the same tape library 108B and mediaagent 144B as the disaster recovery copy rule set 162, although adifferent storage device or media agent could be used in otherembodiments. Finally, the compliance copy rule set 164 specifies thatcopies generated under the compliance copy rule set 164 will be retainedfor 10 years, and will be generated on a quarterly basis.

At step 1, the storage manager 140 initiates a backup operationaccording to the backup copy rule set 160. For instance, a schedulingservice running on the storage manager 140 accesses schedulinginformation from the backup copy rule set 160 or a separate schedulingpolicy associated with the client computing device 102, and initiates abackup copy operation on an hourly basis. Thus, at the scheduled timeslot the storage manager 140 sends instructions to the client computingdevice 102 to begin the backup operation.

At step 2, the file system data agent 142A and the email data agent 142Bresiding on the client computing device 102 respond to the instructionsreceived from the storage manager 140 by accessing and processing theprimary data 112A, 112B involved in the copy operation from the primarystorage device 104. Because the operation is a backup copy operation,the data agent(s) 142A, 142B may format the data into a backup format orotherwise process the data.

At step 3, the client computing device 102 communicates the retrieved,processed data to the first media agent 144A, as directed by the storagemanager 140, according to the backup copy rule set 160. In some otherembodiments, the information management system 100 may implement aload-balancing, availability-based, or other appropriate algorithm toselect from the available set of media agents 144A, 144B. Regardless ofthe manner the media agent 144A is selected, the storage manager 140 mayfurther keep a record in the storage manager database 146 of theassociation between the selected media agent 144A and the clientcomputing device 102 and/or between the selected media agent 144A andthe backup copy 116A.

The target media agent 144A receives the data from the client computingdevice 102, and at step 4 conveys the data to the disk library 108A tocreate the backup copy 116A, again at the direction of the storagemanager 140 and according to the backup copy rule set 160. The secondarystorage device 108A can be selected in other ways. For instance, themedia agent 144A may have a dedicated association with a particularsecondary storage device(s), or the storage manager 140 or media agent144A may select from a plurality of secondary storage devices, e.g.,according to availability, using one of the techniques described in U.S.Pat. No. 7,246,207, which is incorporated by reference herein.

The media agent 144A can also update its index 153 to include dataand/or metadata related to the backup copy 116A, such as informationindicating where the backup copy 116A resides on the disk library 108A,data and metadata for cache retrieval, etc. After the 30 day retentionperiod expires, the storage manager 140 instructs the media agent 144Ato delete the backup copy 116A from the disk library 108A. The storagemanager 140 may similarly update its index 150 to include informationrelating to the storage operation, such as information relating to thetype of storage operation, a physical location associated with one ormore copies created by the storage operation, the time the storageoperation was performed, status information relating to the storageoperation, the components involved in the storage operation, and thelike. In some cases, the storage manager 140 may update its index 150 toinclude some or all of the information stored in the index 153 of themedia agent 144A.

At step 5, the storage manager 140 initiates the creation of a disasterrecovery copy 116B according to the disaster recovery copy rule set 162.For instance, at step 6, based on instructions received from the storagemanager 140 at step 5, the specified media agent 144B retrieves the mostrecent backup copy 116A from the disk library 108A.

At step 7, again at the direction of the storage manager 140 and asspecified in the disaster recovery copy rule set 162, the media agent144B uses the retrieved data to create a disaster recovery copy 116B onthe tape library 108B. In some cases, the disaster recovery copy 116B isa direct, mirror copy of the backup copy 116A, and remains in the backupformat. In other embodiments, the disaster recovery copy 116B may begenerated in some other manner, such as by using the primary data 112A,112B from the primary storage device 104 as source data. The disasterrecovery copy operation is initiated once a day and the disasterrecovery copies 116B are deleted after 60 days.

At step 8, the storage manager 140 initiates the creation of acompliance copy 116C, according to the compliance copy rule set 164. Forinstance, the storage manager 140 instructs the media agent 144B tocreate the compliance copy 116C on the tape library 108B at step 9, asspecified in the compliance copy rule set 164. In the example, thecompliance copy 116C is generated using the disaster recovery copy 116B.In other embodiments, the compliance copy 116C is instead generatedusing either the primary data 112B corresponding to the email sub-clientor using the backup copy 116A from the disk library 108A as source data.As specified, in the illustrated example, compliance copies 116C arecreated quarterly, and are deleted after ten years.

While not shown in FIG. 1E, at some later point in time, a restoreoperation can be initiated involving one or more of the secondary copies116A, 116B, 116C. As one example, a user may manually initiate a restoreof the backup copy 116A by interacting with the user interface 158 ofthe storage manager 140. The storage manager 140 then accesses data inits index 150 (and/or the respective storage policy 148A) associatedwith the selected backup copy 116A to identify the appropriate mediaagent 144A and/or secondary storage device 108A.

In other cases, a media agent may be selected for use in the restoreoperation based on a load balancing algorithm, an availability basedalgorithm, or other criteria. The selected media agent 144A retrievesthe data from the disk library 108A. For instance, the media agent 144Amay access its index 153 to identify a location of the backup copy 116Aon the disk library 108A, or may access location information residing onthe disk 108A itself.

When the backup copy 116A was recently created or accessed, the mediaagent 144A accesses a cached version of the backup copy 116A residing inthe index 153, without having to access the disk library 108A for someor all of the data. Once it has retrieved the backup copy 116A, themedia agent 144A communicates the data to the source client computingdevice 102. Upon receipt, the file system data agent 142A and the emaildata agent 142B may unpackage (e.g., restore from a backup format to thenative application format) the data in the backup copy 116A and restorethe unpackaged data to the primary storage device 104.

Exemplary Applications of Storage Policies

The storage manager 140 may permit a user to specify aspects of thestorage policy 148A. For example, the storage policy can be modified toinclude information governance policies to define how data should bemanaged in order to comply with a certain regulation or businessobjective. The various policies may be stored, for example, in thedatabase 146. An information governance policy may comprise aclassification policy, which is described herein. An informationgovernance policy may align with one or more compliance tasks that areimposed by regulations or business requirements. Examples of informationgovernance policies might include a Sarbanes-Oxley policy, a HIPAApolicy, an electronic discovery (E-Discovery) policy, and so on.

Information governance policies allow administrators to obtain differentperspectives on all of an organization's online and offline data,without the need for a dedicated data silo created solely for eachdifferent viewpoint. As described previously, the data storage systemsherein build a centralized index that reflects the contents of adistributed data set that spans numerous clients and storage devices,including both primary and secondary copies, and online and offlinecopies. An organization may apply multiple information governancepolicies in a top-down manner over that unified data set and indexingschema in order to permit an organization to view and manipulate thesingle data set through different lenses, each of which is adapted to aparticular compliance or business goal. Thus, for example, by applyingan E-discovery policy and a Sarbanes-Oxley policy, two different groupsof users in an organization can conduct two very different analyses ofthe same underlying physical set of data copies, which may bedistributed throughout the organization.

A classification policy defines a taxonomy of classification terms ortags relevant to a compliance task and/or business objective. Aclassification policy may also associate a defined tag with aclassification rule. A classification rule defines a particularcombination of data criteria, such as users who have created, accessedor modified a document or data object; file or application types;content or metadata keywords; clients or storage locations; dates ofdata creation and/or access; review status or other status within aworkflow (e.g., reviewed or un-reviewed); modification times or types ofmodifications; and/or any other data attributes. A classification rulemay also be defined using other classification tags in the taxonomy. Thevarious criteria used to define a classification rule may be combined inany suitable fashion, for example, via Boolean operators, to define acomplex classification rule. As an example, an E-discoveryclassification policy might define a classification tag “privileged”that is associated with documents or data objects that (1) were createdor modified by legal department staff, (2) were sent to or received fromoutside counsel via email, and/or (3) contain one of the followingkeywords: “privileged” or “attorney,” “counsel”, or other terms.

One specific type of classification tag, which may be added to an indexat the time of indexing, is an entity tag. An entity tag may be, forexample, any content that matches a defined data mask format. Examplesof entity tags might include, e.g., social security numbers (e.g., anynumerical content matching the formatting mask XXX-XX-XXXX), credit cardnumbers (e.g., content having a 13-16 digit string of numbers), SKUnumbers, product numbers, etc.

A user may define a classification policy by indicating criteria,parameters or descriptors of the policy via a graphical user interfacethat provides facilities to present information and receive input data,such as a form or page with fields to be filled in, pull-down menus orentries allowing one or more of several options to be selected, buttons,sliders, hypertext links or other known user interface tools forreceiving user input. For example, a user may define certain entitytags, such as a particular product number or project ID code that isrelevant in the organization.

In some implementations, the classification policy can be implementedusing cloud-based techniques. For example, the storage devices may becloud storage devices, and the storage manager 140 may execute cloudservice provider API over a network to classify data stored on cloudstorage devices.

Exemplary Secondary Copy Formatting

The formatting and structure of secondary copies 116 can vary, dependingon the embodiment. In some cases, secondary copies 116 are formatted asa series of logical data units or “chunks” (e.g., 512 MB, 1 GB, 2 GB, 4GB, or 8 GB chunks). This can facilitate efficient communication andwriting to secondary storage devices 108, e.g., according to resourceavailability. For example, a single secondary copy 116 may be written ona chunk-by-chunk basis to a single secondary storage device 108 oracross multiple secondary storage devices 108. In some cases, users canselect different chunk sizes, e.g., to improve throughput to tapestorage devices.

Generally, each chunk can include a header and a payload. The payloadcan include files (or other data units) or subsets thereof included inthe chunk, whereas the chunk header generally includes metadata relatingto the chunk, some or all of which may be derived from the payload. Forexample, during a secondary copy operation, the media agent 144, storagemanager 140, or other component may divide the associated files intochunks and generate headers for each chunk by processing the constituentfiles.

The headers can include a variety of information such as fileidentifier(s), volume(s), offset(s), or other information associatedwith the payload data items, a chunk sequence number, etc. Importantly,in addition to being stored with the secondary copy 116 on the secondarystorage device 108, the chunk headers can also be stored to the index153 of the associated media agent(s) 144 and/or the index 150. This isuseful in some cases for providing faster processing of secondary copies116 during restores or other operations. In some cases, once a chunk issuccessfully transferred to a secondary storage device 108, thesecondary storage device 108 returns an indication of receipt, e.g., tothe media agent 144 and/or storage manager 140, which may update theirrespective indexes 153, 150 accordingly. During restore, chunks may beprocessed (e.g., by the media agent 144) according to the information inthe chunk header to reassemble the files.

Data can also be communicated within the information management system100 in data channels that connect the client computing devices 102 tothe secondary storage devices 108. These data channels can be referredto as “data streams”, and multiple data streams can be employed toparallelize an information management operation, improving data transferrate, among providing other advantages. Example data formattingtechniques including techniques involving data streaming, chunking, andthe use of other data structures in creating copies (e.g., secondarycopies) are described in U.S. Pat. Nos. 7,315,923 and 8,156,086, and8,578,120, each of which is incorporated by reference herein.

FIGS. 1F and 1G are diagrams of example data streams 170 and 171,respectively, which may be employed for performing data storageoperations. Referring to FIG. 1F, the data agent 142 forms the datastream 170 from the data associated with a client computing device 102(e.g., primary data 112). The data stream 170 is composed of multiplepairs of stream header 172 and stream data (or stream payload) 174. Thedata streams 170 and 171 shown in the illustrated example are for asingle-instanced storage operation, and a stream payload 174 thereforemay include both single-instance (“SI”) data and/or non-SI data. Astream header 172 includes metadata about the stream payload 174. Thismetadata may include, for example, a length of the stream payload 174,an indication of whether the stream payload 174 is encrypted, anindication of whether the stream payload 174 is compressed, an archivefile identifier (ID), an indication of whether the stream payload 174 issingle instanceable, and an indication of whether the stream payload 174is a start of a block of data.

Referring to FIG. 1G, the data stream 171 has the stream header 172 andstream payload 174 aligned into multiple data blocks. In this example,the data blocks are of size 64 KB. The first two stream header 172 andstream payload 174 pairs comprise a first data block of size 64 KB. Thefirst stream header 172 indicates that the length of the succeedingstream payload 174 is 63 KB and that it is the start of a data block.The next stream header 172 indicates that the succeeding stream payload174 has a length of 1 KB and that it is not the start of a new datablock. Immediately following stream payload 174 is a pair comprising anidentifier header 176 and identifier data 178. The identifier header 176includes an indication that the succeeding identifier data 178 includesthe identifier for the immediately previous data block. The identifierdata 178 includes the identifier that the data agent 142 generated forthe data block. The data stream 171 also includes other stream header172 and stream payload 174 pairs, which may be for SI data and/or fornon-SI data.

FIG. 1H is a diagram illustrating the data structures 180 that may beused to store blocks of SI data and non-SI data on the storage device(e.g., secondary storage device 108). According to certain embodiments,the data structures 180 do not form part of a native file system of thestorage device. The data structures 180 include one or more volumefolders 182, one or more chunk folders 184/185 within the volume folder182, and multiple files within the chunk folder 184. Each chunk folder184/185 includes a metadata file 186/187, a metadata index file 188/189,one or more container files 190/191/193, and a container index file192/194. The metadata file 186/187 stores non-SI data blocks as well aslinks to SI data blocks stored in container files. The metadata indexfile 188/189 stores an index to the data in the metadata file 186/187.The container files 190/191/193 store SI data blocks. The containerindex file 192/194 stores an index to the container files 190/191/193.Among other things, the container index file 192/194 stores anindication of whether a corresponding block in a container file190/191/193 is referred to by a link in a metadata file 186/187. Forexample, data block B2 in the container file 190 is referred to by alink in the metadata file 187 in the chunk folder 185. Accordingly, thecorresponding index entry in the container index file 192 indicates thatthe data block B2 in the container file 190 is referred to. As anotherexample, data block B1 in the container file 191 is referred to by alink in the metadata file 187, and so the corresponding index entry inthe container index file 192 indicates that this data block is referredto.

As an example, the data structures 180 illustrated in FIG. 1H may havebeen created as a result of two storage operations involving two clientcomputing devices 102. For example, a first storage operation on a firstclient computing device 102 could result in the creation of the firstchunk folder 184, and a second storage operation on a second clientcomputing device 102 could result in the creation of the second chunkfolder 185. The container files 190/191 in the first chunk folder 184would contain the blocks of SI data of the first client computing device102. If the two client computing devices 102 have substantially similardata, the second storage operation on the data of the second clientcomputing device 102 would result in the media agent 144 storingprimarily links to the data blocks of the first client computing device102 that are already stored in the container files 190/191. Accordingly,while a first storage operation may result in storing nearly all of thedata subject to the storage operation, subsequent storage operationsinvolving similar data may result in substantial data storage spacesavings, because links to already stored data blocks can be storedinstead of additional instances of data blocks.

If the operating system of the secondary storage computing device 106 onwhich the media agent 144 resides supports sparse files, then when themedia agent 144 creates container files 190/191/193, it can create themas sparse files. As previously described, a sparse file is type of filethat may include empty space (e.g., a sparse file may have real datawithin it, such as at the beginning of the file and/or at the end of thefile, but may also have empty space in it that is not storing actualdata, such as a contiguous range of bytes all having a value of zero).Having the container files 190/191/193 be sparse files allows the mediaagent 144 to free up space in the container files 190/191/193 whenblocks of data in the container files 190/191/193 no longer need to bestored on the storage devices. In some examples, the media agent 144creates a new container file 190/191/193 when a container file190/191/193 either includes 100 blocks of data or when the size of thecontainer file 190 exceeds 50 MB. In other examples, the media agent 144creates a new container file 190/191/193 when a container file190/191/193 satisfies other criteria (e.g., it contains fromapproximately 100 to approximately 1000 blocks or when its size exceedsapproximately 50 MB to 1 GB).

In some cases, a file on which a storage operation is performed maycomprise a large number of data blocks. For example, a 100 MB file maybe comprised in 400 data blocks of size 256 KB. If such a file is to bestored, its data blocks may span more than one container file, or evenmore than one chunk folder. As another example, a database file of 20 GBmay comprise over 40,000 data blocks of size 512 KB. If such a databasefile is to be stored, its data blocks will likely span multiplecontainer files, multiple chunk folders, and potentially multiple volumefolders. As described in detail herein, restoring such files may thusrequiring accessing multiple container files, chunk folders, and/orvolume folders to obtain the requisite data blocks.

Example Scalable Information Management System

FIG. 2 is a block diagram illustrating an example of a scalableinformation management system 200. In some embodiments, the scalableinformation management system 200 can include some or all of theembodiments described previously with respect to the informationmanagement systems 100. To simplify discussion, reference numbers arere-used to indicate correspondence between certain referenced elementsof the information management system 200 and the information managementsystem 100. Further, to simplify the illustration, certain elements areomitted from the illustration of the information management system 200,but which may be included in certain embodiments. For example, althoughthe storage manager 140 of the information management system 200 omits ajob agent, the storage manager 140 as illustrated in FIG. 1C may includea jobs agent 156.

The information management system 200 can implement a number ofprocesses in addition to those that have been previously described. Forexample, the information management system 200 may implement a processto reduce the proliferation of virtual machines (VMs) by allocating jobrequests among existing virtual machines. As a second example, theinformation management system 200 can implement a process for groupingvirtual machines and/or virtual machine host systems or providersystems. As a third example, the information management system 200 canimplement a load-balancing process or distribute work among virtualserver agents. Although not limited as such, this load-balancing processmay be used to distribute the load during a backup process. Theseexample processes are described in more detail below with reference toFIGS. 3-5. Further, the example processes are described with respect toa number of example systems of the information management system 200.However, other systems may implement the processes including some of thesystems that have previously been described. Some of the example systemswill now be described.

As previously described, the information management system 200 mayinclude a number of client computing devices 102. In addition to theapplications 110 and the data agents 142 (not shown in FIG. 2), thecomputing devices may include a number of virtual machines 204. Thevirtual machines 204 may include any type of virtual machine created forany purpose. For example, the virtual machines 204 may be Windows-basedvirtual machines, UNIX-based virtual machines, or Apple OS-based virtualmachines. Further, the virtual machines 204 may be for facilitatingapplication access, emulating hardware, accessing or managing differentdatabases, performing data management, sharing computing resources amongmultiple user, or for any other purpose.

In addition to the virtual machines 204, the client computing devices102 may include a virtual machine monitor 206 or a hypervisor. Thevirtual machine monitor 206 may be any type of virtual machine monitorfor managing the virtual machines 204. For example, the virtual machinemonitor 206 may be a native or bare metal hypervisor (e.g., Oracle VMServer or Microsoft Hyper-V) or a hosted hypervisor run within anoperating system environment (e.g., VMware Workstation or VirtualBox).In some cases, multiple virtual machine monitors 206 may be included bythe client computing devices 102. For example, a virtual machine monitor206 may be included for one type or group of virtual machines andanother virtual machine monitor 206 may be included for another type orgroup of virtual machines.

In addition to the client computing devices 102, the informationmanagement system 200 includes a number of server computing devices 212.Like the client computing devices 102, a server computing device 212 mayinclude a number of virtual machines 204 and a virtual machine monitor206. Although the terms client and server are used with respect to thecomputing devices of the primary storage subsystem 117, this disclosureis not limited to a client/server computing infrastructure, but mayinclude other types of computing systems and/or network configurations.

As illustrated in FIG. 2, the information management system 200 mayinclude a number of virtual server agents 210A, 210B, 210C (referred tocollectively as virtual server agents or VSAs 210). The virtual serveragents 210 can include any type of agent or system for managingoperations between the primary storage subsystem 117 and the secondarystorage subsystem 118 with respect to the virtual machines 204. Forexample, the virtual server agents 210 may facilitate or implement abackup and/or restoration process for backing/restoring files of avirtual machine 204 or a virtual disk to/from the secondary storagesubsystem 118. As another example, the virtual server agents 210 mayfacilitate deduplication or encryption/decryption of files or virtualdisks to be stored to or restored from the secondary storage subsystem118. The virtual server agents may be standalone computing systems(e.g., the virtual server agent 210B). Alternatively, the virtual serveragents may be a hardware and/or software module included with one ormore of the computing systems hosting the virtual machines (e.g., thevirtual server agents 210A of the server computing devices 212).

In some embodiments, the virtual server agents 210 may be grouped. Forexample, virtual server agents 210A may be grouped and may be configuredto manage operations and interactions between the server computingdevices 212 and the secondary storage subsystem 118. As a secondexample, the virtual server agents 210C may be grouped and may beconfigured to manage operations and interactions between the servercomputing device 212 and the secondary storage subsystem 118 instead ofor in addition to the virtual serve agents 210A.

Each of the virtual server agents 210 may include one or more dataconnections, data paths, data streams, or streams to the media agents144 hosted by the secondary storage computing devices 106. Via thestreams, the virtual machines, files accessed via the virtual machines,and/or virtual disks of the virtual machines may be communicated to/fromthe secondary storage subsystem 118. These data connections orcommunication paths are illustrated by the solid line arrows between thevirtual server agents 210 and the secondary storage computing devices106 indicating paths for data transfer. Although not illustrated, insome cases, commands may also be communicated from a system of thesecondary storage subsystem 118 to a virtual server agent 210 via acommand communication channel. In some cases, each communication channelbetween a virtual server agent 210 and a media agent 144 may include asingle data stream. Alternatively, a communication channel may includemultiple data streams.

Information management system 200 may also include one or more VSAcoordinators 202A and 202B (referred to collectively as VSA coordinators202). The VSA coordinators 202 may manage or help distribute jobrequests among virtual server agents 210 assigned to one or more virtualmachines 204. For example, the storage manager 140 may determine, basedfor example on a backup policy stored at the repository 146, that thevirtual machines 204 of the server computing devices 212 are scheduledfor backup. Consequently, the storage manager 140 may provide a jobrequest to the VSA coordinator 202A to backup the virtual machines 204of the server computing devices 212. The VSA coordinator 202A may selectone or more VSAs (e.g., the virtual server agents 210C) assigned to thevirtual machines 204 of the server computing devices 212 to facilitatethe scheduled backup to the secondary storage subsystem 118. Further, insome cases, the VSA coordinator 202A may distribute the virtual machines204 of the server computing devices 212 among the virtual server agentsincluded in the group of virtual server agents 210C.

As indicated by the dashed line arrows between the virtual server agents210 and the VSA coordinators 202, a virtual server agent 210 may receivecommands and/or control data from the VSA coordinators 202. In someembodiments, the VSA coordinators 202 may be standalone systems asindicated by the VSA coordinator 202B. In other embodiments, the VSAcoordinators 202 may be included as part of the storage manager 140 asillustrated by the VSA coordinator 202A.

In some instances, a virtual server agent 210 may serve as a VSAcoordinator 202. For example, when a job request is received by a groupof virtual server agents associated with a set of virtual machines, avirtual server agent from the group of virtual server agents maydesignate itself or may be designated as the VSA coordinator using aleader selection algorithm. This leader selection algorithm may includeany type of algorithm for selecting a leader among a group of systems.For example, the leader selection algorithm may be based on a roundrobin algorithm where the leader rotates for each new job request. Asanother example, the leader selection algorithm may determine the leastbusy virtual server agent and select that server agent as the VSAcoordinator for the current job request, or for a particular time periodor set of job requests.

As previously stated, virtual machines 204 and/or virtual machineprovider system or hosts (e.g., the server computing devices 212) may becategorized or grouped together. Further, a set of virtual server agents210 may be grouped together based on characteristics or the virtualserver agents. In some cases, the set of virtual server agents may begrouped solely based on their assignment to the same set of virtualmachines and/or virtual machine provider systems or hosts.

In some embodiments, the VSA coordinator 202 may group the virtualmachine 204 and/or the virtual machine provider systems (e.g., theserver computing devices 212). For example, the VSA coordinator 202 mayidentify a number of characteristics associated with one or morecomputing devices configured to host virtual machines 204. The VSAcoordinator 202 may then group the computing devices based on theidentified characteristics. After grouping the computing devices, theVSA coordinator may assign one or more virtual server agents to thegroup of computing devices based on characteristics of the virtualserver agents (e.g., geographic location of the virtual server agents,and network location of the virtual server agents, or the media agentsto which the virtual server agents have established communicationstreams). In some embodiments, virtual machines 204 and/or virtualmachine provider systems may be grouped by a virtual server agent, whichin some cases may be selected by the VSA coordinator 202.

Further, in some embodiments the VSA coordinator 202 may perform aload-balancing operation with respect to the virtual server agents 210.For example, when an operation, such as a backup operation, isinitiated, the VSA coordinator 202 may distribute the virtual machines204 among the assigned virtual server agents 210 based on the capacityof each of the virtual server agents 210, the size of each of thevirtual machines 204, and/or the number of streams between each of thevirtual server agents and the media agents of the secondary storagesubsystem 118.

As illustrated in FIG. 2, the information management system 200 mayfurther include a virtual machine management interface 245, which whenimplemented in software may sometimes be referred to as VM navigationsoftware. The VM management interface 245 can include any systemimplemented in hardware and/or software that can provide a centralizedplatform for managing virtual infrastructure. The centralized platformallows visibility into the configuration of the virtual machines 204within the information management system 200. The VM managementinterface 245 can store information about the structural relationshipbetween physical servers or hosts, resource pools or store devices(e.g., the primary storage devices 104), and virtual machines 204 in theinformation management system 200. Examples of a VM management interface245 include VMware vCenter™, Microsoft System Center Virtual MachineManager®, and the like. The VM management interface 245 can interfacewith the VM monitors 206 to retrieve information about the virtualmachines 204, which may be stored in a database or repository associatedwith the VM management interface 245. Examples of the stored informationcan include a name, an address, other identifying information of eachhost and primary storage device 104 associated with the virtual machines204 in the information management system 200, status information foreach virtual machine 204, type of each virtual machine 204, identity ofassociated virtual server agents 210, an assigned secondary storagecomputing device 106, if any, and any other information that may beassociated with the virtual machines 204.

In some embodiments, the VM management interface 245 may presentinformation associated with the VMs to a user (e.g., an administrator).Further, the VM management interface 245 may be utilized by a user tomanage the virtual machines 204 across one or more host systems (e.g.,the client computing devices 102 and/or server computing devices 212).

Further, in some implementations, the VM management interface 245 mayinclude the VSA coordinator 202. Alternatively, the VM managementinterface 245 may be separate from the VSA coordinator 202. In some suchcases, the VM management interface 245 may interact with the VSAcoordinator 202 to obtain information regarding relating to the VSAgroups and/or VSAs 210. Further, in some cases, the VM managementinterface 245 may be used to configure, manage, or control the VSAs 210by interacting with the VSA coordinators 202. In some embodiments, oneof the virtual machine management interface 245 and the VSA coordinator202 may be optional.

To simplify the illustration, the VM management interface 245 isillustrated in FIG. 2 as communicating with the storage manager 140, theclient computing devices 102, and the virtual server agent 210B.However, the VM management interface 245 is not limited as such.Instead, as described above, the VM management interface 245 maycommunicate with one or more of the VSA coordinators 202, virtual serveragents 210, and/or virtual machine monitors 206.

Example Virtual Machine Job Allocation Process

FIG. 3 illustrates a flowchart for an example virtual machine joballocation process 300. The process 300 can be implemented, at least inpart, by any system that can allocate a job request to a virtual machinefrom among a set of virtual machines based at least partially on theload of each of the virtual machines from the set of virtual machines.Advantageously, in certain embodiments, by allocating job requests toexisting virtual machines, the proliferation of new virtual machines maybe reduced in the information management system 200. By reducing theproliferation of new virtual machines, resource consumption canconsequently be reduced. For example, in some cases, the number ofserver computing devices 212 maintained in the information managementsystem 200 may be reduced. In certain embodiments, the process 300 maybe implemented, in whole or in part, by a storage manager 140, a VSAcoordinator 202, a VM management interface 245, and/or a virtual serveragent 210, to name a few. Although any number of systems, in whole or inpart, can implement the process 300, to simplify discussion, portions ofthe process 300 will be described with reference to particular systems.

The process 300 begins at block 302 where, for example, a VSA (e.g., VSA210B) receives a new job request. This job request may be received froma VSA coordinator (e.g., VSA coordinator 202A), from a jobs agent 156,from a VM management interface 245, or from any other system that mayprovide a job request. In some embodiments, the job request may bereceived from another VSA, such as a VSA serving as a VSA coordinatorfor a group of virtual machines. In some cases, the job request may bereceived by the VSA from itself, such as when the VSA serves as a VSAcoordinator and in its capacity as VSA coordinator selects itself toprocess the job request. The VSA receiving the job request may be one ofa number of VSAs assigned to at least partially manage an assigned setof virtual machines.

At block 304, the VSA determines a load for the virtual machines 204assigned to the VSA. The VSA may determine the load of the virtualmachines by, for example, accessing one or more virtual machine monitors206 associated with the virtual machines 204 and/or one or more dataagents associated with the virtual machine. Alternatively, or inaddition, the VSA may determine the load for one or more of the virtualmachines 204 by tracking and/or accessing a table that tracks jobs orprocesses that have been assigned to the one or more virtual machines204. In certain embodiments, the VSA is able to track the jobs assignedto the virtual machines 204 because the VSA assigns to and/or filtersjob requests for the virtual machines 204. In certain embodiments, theVSA may determine the load for a subset of virtual machines that areassigned to the VSA, which may be assigned based on a type of thevirtual machine 204 and/or the type of jobs to be allocated to thevirtual machines 204. In other words, in some cases, a subset of virtualmachines may be allocated for one particular job type and another subsetof virtual machines may be allocated for another job type. In suchcases, the VSA may limit its analysis of load to the virtual machinesthat are allocated to the job type of the job request received at theblock 302. In some embodiments, the VSA may determine the load for thevirtual machines 204 by accessing or requesting load or statusinformation from the VM management interface 245.

The VSA determines at decision block 306 whether there are any virtualmachines with a load that satisfies a threshold. Further, in some cases,the decision block 306 may determine whether the VMs with a load thatsatisfies the threshold is a non-empty set. In some cases, determiningwhether the load satisfies a threshold may include determining whetherthe load is below a threshold and/or whether the load is at or below athreshold. In some instances, the load may be preset by, for example, anadministrator of the information management system 200. Further, in somecases, the threshold may be based at least partially on the job requestor a type of job associated with the job request. Moreover, in somecases, the threshold may be based at least partially on the anticipatedjob load from the job request received at the block 302.

If the VSA determines at the decision block 306 that there is a virtualmachine with a load below a threshold, the VSA, at block 308, selects avirtual machine from the set of virtual machines that the VSA identifiedas having a load below the threshold. The set of virtual machines maycomprise the virtual machines identified at the decision block 306. Toselect the virtual machine from the set of identified virtual machinesat the block 308, the VSA may use a round robin selection scheme, or anyother type of load balancing selection scheme. In some cases, thevirtual machine may be selected at random. In other cases, a weightedround robin algorithm or other weighted selection algorithm may be usedto select the virtual machine from the set of virtual machines with aload below the threshold. For example, virtual machines may be weightedbased on the capabilities of the computing system (e.g., clientcomputing device 102 or server computing device 212) hosting the virtualmachines. For instance, a host machine with more memory or a newergeneration of processors may be weighted higher than a host machine withless memory or an older generation of processors such that the hostmachine with more memory or a newer generation of processors is selectedmore frequently than the host machine with less memory or olderprocessors. As another example, a virtual machine may be selected basedon the ability to access data or backup the virtual machine without anetwork. For instance, some virtual machines may be able to access datausing a hotadd feature without accessing a network. The hotadd featuremay enable accessing data or a new virtual disk without shutting downthe virtual machine. Further, in some cases, the virtual machine may belocated on the same datastore or repository as a virtual disk to beaccessed via hotadd thereby enabling loading a new disk withoutaccessing a network. In some cases, the virtual machine may access datausing a storage area network (SAN) communicating over a fibre channel.In some embodiments, a virtual machine may be selected based on itsability to access data or be backed up over the SAN without accessing ortransmitting the data over a LAN or other network that may be createdbetween the VM host systems.

At block 310, the VSA assigns the job to the selected virtual machinethat was selected at the block 308. Assigning the job to the selectedvirtual machine may include providing the job request to the selectedvirtual machine. Further, the block 310 may include updating one or moreload tables associated with the virtual machine and/or set of virtualmachines assigned to or allocated to the VSA. In addition, in somecases, the block 310 may include updating one or more load tablesassociated with one or more additional VSA associated with the virtualmachine. For instance, in some cases a plurality of virtual serveragents may be assigned a set of virtual machines. In such cases, the VSAmay update each of the virtual server agents that have been assigned tothe set of virtual machines. In some embodiments, the block 310 mayinclude updating the VM management interface 245 with the assignmentinformation. Advantageously, in certain embodiments, by updating the VMmanagement interface 245 with the assigned job information, a system oruser (e.g., an administrator) may monitor the status of each of the VMs204 and their assigned jobs or tasks by accessing a single system, theVM management interface 245.

If the VSA determines at the decision block 306 that there are novirtual machines (e.g., a set of identified VMs is an empty set)assigned to the VSA with a load satisfying the threshold (e.g., at orbelow the threshold), the VSA may initiate creation of a new virtualmachine at block 312. Initiating creation of a new virtual machine mayinclude selecting a virtual machine provider system (e.g., clientcomputing device 102 or server computing device 212) to host the newvirtual machine. The virtual machine provider system may be selectedbased on the type of virtual machine to be created, the number ofvirtual machines already hosted by the virtual machine provider system,the type of job associated with the job request, or using any otherfactor or algorithm for selecting a virtual machine provider system.Further, in some cases, the virtual machine provider system may beselected using a load balancing scheme to ensure or reduce theprobability that one virtual machine provider system is associated witha disproportionate load compared to other virtual machine providersystems in a group of virtual machine provider systems assigned to a setof VSAs. Once the virtual machine provider system has been selected, theVSA may use the virtual machine monitor 206 of the selected virtualmachine provider system to create the new virtual machine.

After the new virtual machine has been created, the VSA may assign thejob to the virtual machine at block 314. Assigning the job to the newvirtual machine may include providing the job request to the new virtualmachine. In some cases, the block 314 may include one or more of theembodiments described with respect to the block 310. For example, a loadtable associated with the newly created virtual machine may be updatedto reflect the assignment of the job to the new virtual machine.

Example Virtual Machine Grouping Process

FIG. 4 illustrates a flowchart for an example virtual machine groupingprocess 400. The process 400 can be implemented, at least in part, byany system that can group virtual machines based on virtual machineprovider systems and/or virtual machine host systems. Advantageously, incertain embodiments, by grouping virtual machine provider systems, jobsmay be allocated more efficiently to virtual machines based at leastpartially on the capabilities of the host systems. Further, managementof the virtual machines and/or virtual machine provider systems may besimplified compared to information management systems with non-groupedvirtual machine provider systems. Simplifying management can reducemanagement costs in terms of both time and money. In certainembodiments, the process 400 may be implemented, in whole or in part, bya storage manager 140, a VSA coordinator 202, and/or a VM managementinterface 245, to name a few. Although any number of systems, in wholeor in part, can implement the process 400, to simplify discussion,portions of the process 400 will be described with reference toparticular systems.

The process 400 begins at block 402 where, for example, a VSAcoordinator 202 identifies a set of available virtual machine providersystems. These virtual machine provider systems may include any type ofsystem that is capable of hosting a virtual machine 204. For example,the virtual machine provider systems may include the client computingdevices 102 and/or the server computing devices 212. Further, theavailable virtual machine provider systems may include any computingsystems in the information management system 200 capable of hostingvirtual machines. Alternatively, the available virtual machine providersystems may be limited to computing systems capable of hosting virtualmachines that have been registered with the VSA coordinator 202 and/orthe storage manager 140.

At block 404, the VSA coordinator 202 may access metadata associatedwith the set of available virtual machine provider systems identified atthe block 402. This metadata may include the identity of the features,specifications, and/or capabilities associated with each of theavailable virtual machine provider systems. For example, the metadatamay include an amount of memory, a number of processors, or an amount ofstorage space for a particular virtual machine provider system, to namea few. As another example, the metadata may identify whether aparticular virtual machine provider system is capable of supportinghot-add mode, or the ability to clone a virtual disk such that a virtualmachine may continue running while the virtual disk is backed up to, forexample, a secondary storage system. As yet another example, themetadata may include a geographic location of the virtual machineprovider system, a network location of the virtual machine providersystem, an age or amount of time in service of the virtual machineprovider system, a security level associated with the virtual machineprovider system, and any other information that may be used tocategorize or group a virtual machine provider system with one or moreadditional virtual machine provider systems.

At block 406, the VSA coordinator 202 groups the virtual machineprovider systems into one or more categories based at least partially onthe metadata accessed at the block 404. In some embodiments, the VSAcoordinator 202 may group the virtual machine provider systems based atleast partially on grouping rules. These grouping rules may be accessedfrom the storage manager 140. Alternatively, the grouping rules may bereceived from the virtual machine management interface 245. Further, insome cases, the grouping rules may be generated by a user (e.g., anadministrator). The grouping rules may include any type of rule forgrouping virtual machine provider systems. For example, the groupingrules may be based on one or more types of metadata associated with thevirtual machine provider systems.

The VSA coordinator 202, at block 408, assigns one or more virtualserver agents 210 to each of the virtual machine provider system groupsdetermined at the block 406. Although in some cases a single virtualserver agent may be assigned to a virtual machine provider system group,it is often advantageous to assign multiple virtual server agents. Forone, operations may be completed faster because more streams may bemaintained or initiated between the primary storage system 117 and thesecondary storage system 118 when multiple virtual server agents areassigned to a group. An additional advantage, in some cases, is thateach virtual server agent can serve as a failover virtual server agentfor other virtual server agents assigned to the virtual machine providersystem group. For instance, if a backup operation is in progress, and avirtual server agent fails, rather than the backup operation failing,the virtual machines assigned to the failed virtual server agent forbackup may be reassigned to another virtual server agent in the groupenabling the backup operation to proceed.

In some cases, at least some of the virtual server agents assigned to avirtual machine provider system group may include virtual server agentsexecuting on the virtual machine provider systems of the virtual machineprovider system group. Alternatively, or in addition, the virtual serveragents assigned to a virtual machine provider system group may beseparate computing systems and/or may be executed on separate computingsystems from the virtual machine provider systems included in thevirtual machine provider system group.

In some embodiments, if an additional virtual machine provider system isadded to the information management system 200, the VSA coordinator 202may access metadata for the new virtual machine provider system. The VSAcoordinator 202 may then identify a group from the existing groups ofvirtual machine provider systems based at least partially on themetadata of the newly added virtual machine provider system. The VSAcoordinator 202 may then assign the additional virtual machine providersystem to the identified group. Assigning the additional virtual machineprovider system to the identified group may include updating assignmentinformation of the set of virtual server agents assigned to theidentified group to include the additional virtual machine providersystem. If a group cannot be identified based on the metadata of thenewly added virtual machine, the VSA coordinator 202 may create a newgroup for the additional virtual machine provider system.

In certain implementations, the block 408 may include registering thevirtual machine group with the VM management interface 245. Further, insome cases, the VM management interface 245 may cause the VSAcoordinator 202 to perform the process 400.

A similar process to the process 400 may occur when the configuration ofa virtual machine provider system changes. For example, if the VSAcoordinator 202 detects that the configuration of a virtual machineprovider system has changed, or if an administrator identifies to theVSA coordinator 202 to the configuration of a virtual machine providersystem is changed, the VSA coordinator 202 may access the updatedmetadata for the reconfigured virtual machine provider system. Based onthe updated metadata, the VSA coordinator 202 may reassign the virtualmachine provider system to another group. Alternatively, if anothergroup cannot be identified is associated with the updated metadata ofthe modified virtual machine provider system, the VSA coordinator 202may create a new group or the modified virtual machine provider system.Further the VSA coordinator 202 may update assignment information forset of virtual server agents to include or to remove modified virtualmachine provider system from the systems assigned to the set of virtualserver agents.

In some embodiments, the process 400 may be performed periodically ormay be performed each time a virtual machine provider system is added orremoved from the information management system 200. Further, in somecases, when a VSA is no longer assigned to a virtual machine group orwhen a virtual machine provider system group to which the VSA wasassigned no longer includes any virtual machine provider systems and/orVMs, the VSA may be shut down or deactivated. Alternatively, the VSA maybe reassigned to another virtual machine provider system group.

Example Virtual Server Agent Load Balancing Process

FIG. 5 illustrates a flowchart for an example virtual server agent loadbalancing process 500. The process 500 can be implemented, at least inpart, by any system that can balance the load of a set of virtual serveragents. Advantageously, in certain embodiments, by balancing the load ofthe set of virtual server agents, operations may be completed fasterand/or in a more efficient manner. In certain embodiments, the process500 may be implemented, in whole or in part, by a storage manager 140, aVSA 210, a VM management interface 245, and a VSA coordinator 202, toname a few. Although any number of systems, in whole or in part, canimplement the process 500, to simplify discussion, portions of theprocess 500 will be described with reference to particular systems.

It is of note that the process 500 may be used with respect to a numberof types of operations including, for example, deduplication, fileand/or virtual disk restoration, and file and/or virtual diskdecryption/encryption, to name a few. Further, the process 500 may beused with respect to any type of operation that may involvecommunicating with the secondary storage subsystem 118. However, tosimplify discussion, and not to limit the process, the process 500 willbe described primarily in the context of backup.

The process 500 begins at block 502 where, for example, a VSAcoordinator 202 identifies a number of virtual machines to backup. Thevirtual machines may be identified in response to a backup command or ascheduled backup process. For example, a set of virtual machines may bescheduled for backup on a nightly, weekly, or monthly basis. Further,the set of virtual machines for backup may be identified based on agrouping of the virtual machines and/or a grouping of the virtualmachine provider systems that host the set of virtual machines. In somecases, the set of virtual machines identified for backup may beidentified based on the set of virtual server agents assigned to thevirtual machines. In some embodiments, the virtual machines identifiedfor backup may be identified by a user (e.g., an administrator) via, forexample, the VM management interface 245. In some implementations,virtual machines may be identified for backup based on one or morebackup policies or other virtual machine management policies. Thesepolicies may be stored at or implemented by the storage manager 140, avirtual machine management interface 245, and/or a VSA coordinator 202.Further, a determination of whether to implement one or more of themanagement policies may be made based on one or more factors associatedwith the virtual machines, such as instantiation time, time of lastbackup, type of VM, size of the VM, etc. In some cases, at least some ofthe factors may be based on the VSAs 210 associated with the VMs.

At block 504, the VSA coordinator 202 may access metadata associatedwith the virtual machines identified at the block 502. The metadata maybe accessed from a table at a database or repository associated with thevirtual machines and/or host systems of the virtual machines. In somecases, the VSA coordinator 202 may access the metadata by communicatingwith one or more virtual machine monitors 206 that facilitate managementof the virtual machines 204 identified at the block 502. Alternatively,or in addition, the VSA coordinator 202 may obtain access to themetadata by communicating with the one or more virtual server agents 210assigned to the virtual machines identified at the block 502 and/or thehost systems of the virtual machines.

The VSA coordinator 202, at block 506, identifies a number of virtualserver agents 210 available to facilitate backup of the set of virtualmachines identified at the block 502. The set of virtual server agents210 may be VSAs that have been assigned to the set of virtual machinesand/or host systems of the virtual machines. For example, in referenceto FIG. 2, the virtual machines identified for backup at the block 502include the virtual machines hosted by the server computing devices 212,the set of VSAs identified at the block 506 may include one or more ofthe virtual server agents 210A and virtual server agents 210C.

At block 508, the VSA coordinator 202 determines a number of streamsavailable to each virtual server agent from the number of virtual serveragents identified at the block 506. The streams may be identified byaccessing metadata associated with each of the identified virtual serveragents. Further, the number of available streams may be based at leastpartially on a number of data paths and/or communication channelsbetween the virtual server agents and one or more media agents of thesecondary storage subsystem 118. In some embodiments one or more of theblocks 506 and 508 may be optional. For example, in some cases the VSAcoordinator 202 may determine a number of streams associated with agrouping of virtual machines and/or host computing systems of thevirtual machines.

In some embodiments, the block 508 may include accessing and/ordetermining additional metadata associated with the virtual serveragents identified at the block 506. This metadata may include any typeof information related to the load, capacity, or features of the virtualserver agents. For example, the metadata may identify processingcapacity or storage capacity of a virtual server agent, the number ofprocessors, the type of processors, or the network bandwidth of eachvirtual server agent.

At block 510, the VSA coordinator 202 distributes the virtual machinesidentified at the block 502 among the virtual server agents identifiedat the block 506 for backup to the secondary storage subsystem 118 basedat least partially on the metadata associated with the virtual machinesand the number of streams available to each virtual server agent. Forexample, the virtual machines may be distributed such that a virtualserver agent with more available streams or a larger available bandwidthreceives larger virtual machines while a virtual server agent with lessavailable streams or a smaller available bandwidth may receive smallervirtual machines. As a second example, a virtual server agent with threestreams may receive three virtual machines to backup, a virtual serveragent with two streams may receive to virtual machines to backup, and avirtual server agent with one stream may receive one virtual machine tobackup. In some embodiments, the block 510 may include distributing thevirtual machine among the virtual server agents based partially on themetadata associated with the virtual server agents, such as the age ofthe virtual server agent or the geographic and/or network location ofthe virtual server agent.

In some cases, each of the virtual machines may be assigned to a virtualserver agent for backup as part of a finite process. In other words,virtual machines may be queued for backup to a selected virtual serveragent upon initiation of the backup operation or at the time of thescheduled backup. However, in other cases, virtual machines may beassigned to a virtual server agent on a rolling basis as a virtualserver agent gains capacity to process the virtual machine, such as atthe completion of the backup of another virtual machine. In other words,a virtual machine may only be assigned to the virtual server agent at atime that the virtual server agent is ready to begin processing thebackup of the virtual machine. Advantageously, in certain embodiments,by assigning virtual machines to a virtual server agent for backup onlywhen the virtual server agent is ready to begin backing up the virtualmachine, load-balancing may be improved. For instance, in a case wherethere are ten virtual machines to backup and two virtual server agents,a round robin allocation performed at the start of backup would resultin each virtual server agent being assigned five virtual machines tobackup. In cases where the virtual machines are equal or close in size,five virtual machines per virtual server agent may be optimal. However,in cases where the virtual machines differ substantially in size (e.g.,by a factor 2 or 3), or the virtual server agents are unequal incapacity (e.g., network bandwidth or number of processors), such an evendistribution may be suboptimal for completing backup in the shortestamount of time. Thus, in some cases, assigning a virtual machine forbackup as a virtual server agent becomes available may be preferred.

In some cases the virtual machines may be assigned to the virtual serveragents for backup using a round robin selection process. Alternatively,or in addition, virtual machines may be assigned to the virtual serveragents for backup using a weighting process. For example, larger virtualmachines, or virtual machines with a larger virtual disk, may beweighted higher than smaller virtual machines, virtual machines with asmaller virtual disk. In such cases, a virtual server agent that isassigned a larger virtual machine for backup may be assigned lessvirtual machines than a virtual server agent that is assigned smallervirtual machines.

Alternatively, or in addition, to the capabilities of the virtual serveragents, a virtual server agent may be selected to backup a particularvirtual machine based at least partially on the media agent to which thevirtual server agent has an available stream. In certain embodiments,rather than distributing the virtual machines to the virtual serveragents, the VSA coordinator 202 may distribute the virtual machines tostreams without considering to which virtual server agent the streambelongs were to which media agent stream communicates with.

In some cases, backing up a virtual machine may include backing up filesor data included in virtual storage of the virtual machine or a virtualdisk. Alternatively, backing up the virtual machine may include backingup a file or a portion of a file that comprises the virtual machine.

TERMINOLOGY

Conditional language, such as, among others, “can,” “could,” “might,” or“may,” unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or steps. Thus, such conditional language is notgenerally intended to imply that features, elements and/or steps are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or without userinput or prompting, whether these features, elements and/or steps areincluded or are to be performed in any particular embodiment.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to.” As used herein, the terms “connected,”“coupled,” or any variant thereof means any connection or coupling,either direct or indirect, between two or more elements; the coupling orconnection between the elements can be physical, logical, or acombination thereof. Additionally, the words “herein,” “above,” “below,”and words of similar import, when used in this application, refer tothis application as a whole and not to any particular portions of thisapplication. Where the context permits, words in the above DetailedDescription using the singular or plural number may also include theplural or singular number respectively. The word “or” in reference to alist of two or more items, covers all of the following interpretationsof the word: any one of the items in the list, all of the items in thelist, and any combination of the items in the list. Likewise the term“and/or” in reference to a list of two or more items, covers all of thefollowing interpretations of the word: any one of the items in the list,all of the items in the list, and any combination of the items in thelist.

Depending on the embodiment, certain acts, events, or functions of anyof the algorithms described herein can be performed in a differentsequence, can be added, merged, or left out altogether (e.g., not alldescribed acts or events are necessary for the practice of thealgorithms). Moreover, in certain embodiments, acts or events can beperformed concurrently, e.g., through multi-threaded processing,interrupt processing, or multiple processors or processor cores or onother parallel architectures, rather than sequentially.

Systems and modules described herein may comprise software, firmware,hardware, or any combination(s) of software, firmware, or hardwaresuitable for the purposes described herein. Software and other modulesmay reside on servers, workstations, personal computers, computerizedtablets, PDAs, and other devices suitable for the purposes describedherein. Software and other modules may be accessible via local memory,via a network, via a browser, or via other means suitable for thepurposes described herein. Data structures described herein may comprisecomputer files, variables, programming arrays, programming structures,or any electronic information storage schemes or methods, or anycombinations thereof, suitable for the purposes described herein. Userinterface elements described herein may comprise elements from graphicaluser interfaces, command line interfaces, and other suitable interfaces.

Further, the processing of the various components of the illustratedsystems can be distributed across multiple machines, networks, and othercomputing resources. In addition, two or more components of a system canbe combined into fewer components. Various components of the illustratedsystems can be implemented in one or more virtual machines, rather thanin dedicated computer hardware systems. Likewise, the data repositoriesshown can represent physical and/or logical data storage, including, forexample, storage area networks or other distributed storage systems.Moreover, in some embodiments the connections between the componentsshown represent possible paths of data flow, rather than actualconnections between hardware. While some examples of possibleconnections are shown, any of the subset of the components shown cancommunicate with any other subset of components in variousimplementations.

Embodiments are also described above with reference to flow chartillustrations and/or block diagrams of methods, apparatus (systems) andcomputer program products. Each block of the flow chart illustrationsand/or block diagrams, and combinations of blocks in the flow chartillustrations and/or block diagrams, may be implemented by computerprogram instructions. Such instructions may be provided to a processorof a general purpose computer, special purpose computer, or otherprogrammable data processing apparatus to produce a machine, such thatthe instructions, which execute via the processor of the computer orother programmable data processing apparatus, create means forimplementing the acts specified in the flow chart and/or block diagramblock or blocks.

These computer program instructions may also be stored in anon-transitory computer-readable memory that can direct a computer orother programmable data processing apparatus to operate in a particularmanner, such that the instructions stored in the computer-readablememory produce an article of manufacture including instruction meanswhich implement the acts specified in the flow chart and/or blockdiagram block or blocks. The computer program instructions may also beloaded onto a computer or other programmable data processing apparatusto cause a series of operations to be performed on the computer or otherprogrammable apparatus to produce a computer implemented process suchthat the instructions which execute on the computer or otherprogrammable apparatus provide steps for implementing the acts specifiedin the flow chart and/or block diagram block or blocks.

Any patents and applications and other references noted above, includingany that may be listed in accompanying filing papers, are incorporatedherein by reference. Aspects of the invention can be modified, ifnecessary, to employ the systems, functions, and concepts of the variousreferences described above to provide yet further implementations of theinvention.

These and other changes can be made to the invention in light of theabove Detailed Description. While the above description describescertain examples of the invention, and describes the best modecontemplated, no matter how detailed the above appears in text, theinvention can be practiced in many ways. Details of the system may varyconsiderably in its specific implementation, while still beingencompassed by the invention disclosed herein. As noted above,particular terminology used when describing certain features or aspectsof the invention should not be taken to imply that the terminology isbeing redefined herein to be restricted to any specific characteristics,features, or aspects of the invention with which that terminology isassociated. In general, the terms used in the following claims shouldnot be construed to limit the invention to the specific examplesdisclosed in the specification, unless the above Detailed Descriptionsection explicitly defines such terms. Accordingly, the actual scope ofthe invention encompasses not only the disclosed examples, but also allequivalent ways of practicing or implementing the invention under theclaims.

To reduce the number of claims, certain aspects of the invention arepresented below in certain claim forms, but the applicant contemplatesthe various aspects of the invention in any number of claim forms. Forexample, while only one aspect of the invention is recited as ameans-plus-function claim under 35 U.S.C sec. 112(f) (AIA), otheraspects may likewise be embodied as a means-plus-function claim, or inother forms, such as being embodied in a computer-readable medium. Anyclaims intended to be treated under 35 U.S.C. §112(f) will begin withthe words “means for”, but use of the term “for” in any other context isnot intended to invoke treatment under 35 U.S.C. §112(f). Accordingly,the applicant reserves the right to pursue additional claims afterfiling this application, in either this application or in a continuingapplication.

What is claimed is:
 1. A method of virtual server agent load balancing,the method comprising: by a virtual server agent coordinator comprisingcomputer hardware: identifying a set of virtual machines for backup to asecondary storage system, the set of virtual machines hosted by a set ofvirtual machine provider systems, the set of virtual machine providersystems included in a primary storage system; identifying a set ofvirtual server agents available to backup data from the set of virtualmachines to the secondary storage system; determining a number of datastreams available to each virtual server agent from the set of virtualserver agents; and distributing the set of virtual machines among theset of virtual server agents based at least partially on the number ofdata streams available to each of the virtual server agents and a sizeof each virtual machine from the set of virtual machines, wherein afirst virtual machine with a first size is distributed to a firstvirtual server agent from the set of virtual server agents and a secondvirtual machine with a second size is distributed to a second virtualserver agent from the set of virtual server agents, and wherein thefirst size is less than the second size and the first virtual serveragent is associated with less number of available data streams than anumber of available data streams associated with the second virtualserver agent.
 2. The method of claim 1, wherein the set of virtualserver agents are identified from among a subset of virtual serveragents assigned to the set of virtual machines.
 3. The method of claim1, further comprising accessing metadata for each virtual machine fromthe set of virtual machines.
 4. The method of claim 3, wherein saiddistributing is based at least partially on the metadata for each of thevirtual machines.
 5. The method of claim 1, wherein said distributing isbased on a round-robin allocation of the set of virtual machines.
 6. Themethod of claim 1, wherein the number of data streams available to eachvirtual server agent is based at least partially on a number ofcommunication channels between the virtual server agent and a set ofmedia agents included in the secondary storage system.
 7. The method ofclaim 1, further comprising accessing metadata for each virtual serveragent from the set of virtual server agents.
 8. The method of claim 7,wherein said distributing is based at least partially on the metadatafor each virtual server agent.
 9. The method of claim 1, furthercomprising backing up the set of virtual machines to the secondarystorage system via the set of virtual server agents.
 10. The method ofclaim 1, wherein each data stream comprises a data connection between avirtual server agent and a media agent included in the secondary storagesystem.
 11. A system for virtual server agent load balancing, the systemcomprising: a virtual server agent coordinator comprising computerhardware, the virtual server agent coordinator configured to: identify aset of virtual machines for backup to a secondary storage system, theset of virtual machines hosted by a set of virtual machine providersystems, the set of virtual machine provider systems included in aprimary storage system; identify a set of virtual server agentsavailable to backup data from the set of virtual machines to thesecondary storage system; determine a number of data streams availableto each virtual server agent from the set of virtual server agents; anddistribute the set of virtual machines among the set of virtual serveragents based at least partially on the number of data streams availableto each of the virtual server agents and a size of each virtual machinefrom the set of virtual machines, wherein a first virtual machine with afirst size is distributed to a first virtual server agent from the setof virtual server agents and a second virtual machine with a second sizeis distributed to a second virtual server agent from the set of virtualserver agents, and wherein the first size is less than the second sizeand the first virtual server agent is associated with less number ofavailable data streams than a number of available data streamsassociated with the second virtual server agent.
 12. The system of claim11, wherein the set of virtual server agents are identified from among asubset of virtual server agents assigned to the set of virtual machines.13. The system of claim 11, wherein the virtual server agent coordinatoris further configured to access metadata for each virtual machine fromthe set of virtual machines, and wherein the virtual server agentcoordinator is further configured to distribute the set of virtualmachines based at least partially on the metadata.
 14. The system ofclaim 11, wherein the number of data streams available to each virtualserver agent is based at least partially on a number of communicationchannels between the virtual server agent and a set of media agentsincluded in the secondary storage system.
 15. The system of claim 11,wherein the virtual server agent coordinator is further configured toaccess metadata for each virtual server agent from the set of virtualserver agents and wherein the virtual server agent coordinator isfurther configured to distribute the set of virtual machines based atleast partially on the metadata.
 16. The system of claim 11, wherein thevirtual server agent coordinator is further configured to cause the setof virtual server agents to backup the set of virtual machines.
 17. Thesystem of claim 16, wherein the virtual server agent coordinator causesthe set of virtual server agents to backup the set of virtual machinesbased on an automated backup schedule.
 18. The system of claim 11,wherein the virtual server agent coordinator is further configured todistribute the set of virtual machines based at least partially on aweight associated with each virtual machine.